Synopsis

Take a data structure in Perl, and automatically write a Python3 script using matplotlib to generate an image. The Python3 script is saved in /tmp, to be edited at the user's discretion. Requires python3 and matplotlib installations.

My aim is to simplify the most common tasks as much as possible. In my opinion, using this module is much easier than matplotlib itself.

Single Plots

Simplest use case:

use Matplotlib::Simple;
bar({
   'output.file'     => '/tmp/gospel.word.counts.png',
   data              => {
	  Matthew => 18345,
	  Mark    => 11304,
	  Luke    => 19482,
	  John    => 15635,
   }
});

A more complete (and slightly faster execution):

use Matplotlib::Simple;
plt({
   'output.file'     => '/tmp/gospel.word.counts.png',
   'plot.type'       => 'bar',
   data              => {
	  Matthew => 18345,
	  Mark    => 11304,
	  Luke    => 19482,
	  John    => 15635,
   }
});
gospel word counts

Multiple Plots

Having a plots argument as an array lets the module know to create subplots:

use Matplotlib::Simple 'plt';
plt({
	'output.file'	=> 'svg/pies.png',
	plots             => [
    {
			data	=> {
			 Russian => 106_000_000,  # Primarily European Russia
    		 German => 95_000_000,    # Germany, Austria, Switzerland, etc.
    		},
    		'plot.type'	=> 'pie',
    		title       => 'Top Languages in Europe',
		    suptitle    => 'Pie in subplots',
		},
    	{
    		data	=> {
    		 Russian => 106_000_000,  # Primarily European Russia
    		 German => 95_000_000,    # Germany, Austria, Switzerland, etc.
	    	},
	    	'plot.type'	=> 'pie',
	    	title       => 'Top Languages in Europe',
	    },
    ],
    ncols    => 2,
});

which produces the following subplots image:

pies

bar, barh, boxplot, hexbin, hist, hist2d, imshow, pie, plot, scatter, and violinplot all match the methods in matplotlib itself.

Options

sharex and sharey are both implemented at the plot, rather than subplot, level. See Matplotlib's documentation for more clarity.

Color Bars (colorbars)

Colarbar args attempt to match matplotlib closely

| Option | Description | Example | | -------- | ------- | ------- |cbdrawedges | Whether to draw lines at color boundaries | cbdrawedges => 1| |cblabel | The label on the colorbar's long axis | cblabel => 1 | |cblocation | of the colorbar None or {'left', 'right', 'top', 'bottom'} | | |cborientation | # None or {vertical, horizontal} | |cbpad | pad : float, default: 0.05 if vertical, 0.15 if horizontal; Fraction of original Axes between colorbar and new image Axes |cb_logscale | Perl true (anything but 0) or false (0)| | |shared.colorbar | share colorbar between different plots: specify plot indices | 'shared.colorbar' => [0,1]|

Size/Dimensions of output file

| Option | Description | Example | | -------- | ------- | ------- | |scale | scale/multiply the size of the output figure | scale => 2.4| |scalex | scale/multiply the x-axis only | scalex => 2.4 | |scaley | scale/multiply the y-axis only | scalex => 1.4 |

Examples/Plot Types

Consider the following helper subroutines to generate data to plot:

sub linspace { # mostly written by Grok
   my ($start, $stop, $num, $endpoint) = @_; # endpoint means include $stop
   $num = defined $num ? int($num) : 50; # Default to 50 points
   $endpoint = defined $endpoint ? $endpoint : 1; # Default to include endpoint
   return () if $num < 0; # Return empty array for invalid num
   return ($start) if $num == 1; # Return single value if num is 1
   my (@result, $step);

   if ($endpoint) {
       $step = ($stop - $start) / ($num - 1) if $num > 1;
       for my $i (0 .. $num - 1) {
         $result[$i] = $start + $i * $step;
       }
  } else {
     $step = ($stop - $start) / $num;
     for my $i (0 .. $num - 1) {
	    $result[$i] = $start + $i * $step;
     }
  }
   return @result;
}

sub generate_normal_dist {
	my ($mean, $std_dev, $size) = @_;
	$size = defined $size ? int $size : 100; # default to 100 points
	my @numbers;
	for (1 .. int($size / 2) + 1) {# Box-Muller transform
		my $u1 = rand();
		my $u2 = rand();
    	my $z0 = sqrt(-2.0 * log($u1)) * cos(2.0 * 3.141592653589793 * $u2);
	    my $z1 = sqrt(-2.0 * log($u1)) * sin(2.0 * 3.141592653589793 * $u2); # Scale and shift to match mean and std_dev
	    push @numbers, ($z0 * $std_dev + $mean, $z1 * $std_dev + $mean);
	} # Trim to exact size if needed
    @numbers = @numbers[0 .. $size - 1] if @numbers > $size;
	@numbers = map {sprintf '%.1f', $_} @numbers;
    return \@numbers;
}
sub rand_between {
    my ($min, $max) = @_;
    return $min + rand($max - $min)
}

Barplot/bar/barh

Plot a hash or a hash of arrays as a boxplot

Options

| Option | Description | Example | | -------- | ------- | ------- |color| :mpltype:color or list of :mpltype:color, optional; The colors of the bar faces. This is an alias for facecolor. If both are given, facecolor takes precedence # if entering multiple colors, quoting isn't needed; as of version 0.23, colors can be given as a hash |color => ['red', 'orange', 'yellow', 'green', 'blue', 'indigo', 'fuchsia'], or a single color for all bars color => 'red', or as of version 0.23 color => {A => 'red', B => 'green'} |edgecolor| :mpltype:color or list of :mpltype:color, optional; The colors of the bar edges|edgecolor => 'black' |key.order| define the keys in an order (an array reference)|'key.order' => ['Sun','Mon','Tue','Wed','Thu','Fri','Sat'], |linewidth| float or array, optional; Width of the bar edge(s). If 0, don't draw edges. Only does anything with defined edgecolor|linewidth => 2, |log| bool, default: False; If True, set the y-axis to be log scale.|log = 'True', |stacked| stack the groups on top of one another; default 0 = off|stacked => 1, |width| float only, default: 0.8; The width(s) of the bars. width will be deactivated with grouped, non-stacked bar plots |width => 0.4, |xerr| float or array-like of shape(N,) or shape(2, N), optional. If not None, add horizontal / vertical errorbars to the bar tips. The values are +/- sizes relative to the data: - scalar: symmetric +/- values for all bars # - shape(N,): symmetric +/- values for each bar # - shape(2, N): Separate - and + values for each bar. First row # contains the lower errors, the second row contains the upper # errors. # - None: No errorbar. (Default)|yerr => {'USA' => [15,29], 'Russia' => [199,1000],} |yerr|same as xerr, but better with bar|

an example of multiple plots, showing many options:

single, simple plot

use Matplotlib::Simple 'plt';
plt({
    'output.file'			=> 'output.images/single.barplot.png',
    data	=> { # simple hash
	    Fri => 76, Mon	=> 73, Sat => 26, Sun => 11, Thu	=> 94, Tue	=> 93, Wed	=> 77
    },
    'plot.type'	=> 'bar',
    xlabel		=> '# of Days',
    ylabel		=> 'Count',
    title		=> 'Customer Calls by Days'
});

where xlabel, ylabel, title, etc. are axis methods in matplotlib itself. plot.type, data, fh are all specific to MatPlotLib::Simple. single barplot

multiple plots

plt({
    fh                  => $fh,
    execute				   => 0,
    'output.file'	=> 'output.images/barplots.png',
    plots					=> [
	{ # simple plot
		    data	=> { # simple hash
			    Fri => 76, Mon	=> 73, Sat => 26, Sun => 11, Thu	=> 94, Tue	=> 93, Wed	=> 77
    		},
			'plot.type'	=> 'bar',
		   'key.order'		=> ['Sun','Mon','Tue','Wed','Thu','Fri','Sat'],
	    	suptitle			=> 'Types of Plots', # applies to all
    		color				=> ['red', 'orange', 'yellow', 'green', 'blue', 'indigo', 'fuchsia'],
			edgecolor		=> 'black',
		    set_figwidth	=> 40/1.5, # applies to all plots
    		set_figheight	=> 30/2, # applies to all plots
    		title				=> 'bar: Rejections During Job Search',
			xlabel			=> 'Day of the Week',
			ylabel			=> 'No. of Rejections'
		},
    	{ # grouped bar plot
		    'plot.type'	=> 'bar',
		    data	=> {
			    1941 => {
	    		   UK       => 6.6,
    			   US       => 6.2,
				   USSR     => 17.8,
			       Germany => 26.6
		    	},
	    		1942 => {
    			  UK      => 7.6,
				  US      => 26.4,
		    	  USSR    => 19.2,
			      Germany => 29.7
     			},
				1943 => {
			   	 UK      => 7.9,
			      US      => 61.4,
	    		  USSR    => 22.5,
    			  Germany => 34.9
				},
			    1944 => {
			      UK      => 7.4,
		    	  US      => 80.5,
        		  USSR    => 27.0,
				  Germany => 31.4
			    },
			    1945 => {
			      UK      => 5.4,
		    	  US      => 83.1,
	    		  USSR    => 25.5,
    			  Germany => 11.2 #Rapid decrease due to war's end	
				},
	    	},
    		stacked	=> 0,
			title		=> 'Hash of Hash Grouped Unstacked Barplot',
		    width		=> 0.23,
	    	xlabel	=> 'r"$\it{anno}$ $\it{domini}$"', # italic
    		ylabel	=> 'Military Expenditure (Billions of $)'
		},
	     { # grouped bar plot
		    'plot.type'	=> 'bar',
		    data	=> {
	    		1941 => {
    			  UK      => 6.6,
				  US      => 6.2,
			      USSR    => 17.8,
		    	  Germany => 26.6
	    		},
    			1942 => {
				  UK      => 7.6,
			      US      => 26.4,
		    	  USSR    => 19.2,
	    		  Germany => 29.7
    			},
				1943 => {
				  UK      => 7.9,
			      US      => 61.4,
		     	  USSR    => 22.5,
	    		  Germany => 34.9
    			},
				1944 => {
			      UK      => 7.4,
		    	  US      => 80.5,
	    		  USSR    => 27.0,
    			  Germany => 31.4
				},
			    1945 => {
		    	  UK      => 5.4,
	    		  US      => 83.1,
    			  USSR    => 25.5,
				   Germany => 11.2 #Rapid decrease due to war's end	
    			},
			},
		    stacked	=> 1,
	    	title		=> 'Hash of Hash Grouped Stacked Barplot',
    		xlabel	=> 'r"$\it{anno}$ $\it{domini}$"', # italic
			ylabel	=> 'Military Expenditure (Billions of $)'
		},
	    {# grouped barplot: arrays indicate Union, Confederate which must be specified in options hash
    		data					=> { # 4th plot: arrays indicate Union, Confederate which must be specified in options hash
			 'Antietam'				=> [ 12400, 10300 ],
		     'Gettysburg'			=> [ 23000, 28000 ],
	    	 'Chickamauga'			=> [ 16000, 18000 ],
    		 'Chancellorsville'	=> [ 17000, 13000 ],
			 'Wilderness'			=> [ 17500, 11000 ],
		     'Spotsylvania'		=> [ 18000, 12000 ],
	    	 'Cold Harbor'			=> [ 12000, 5000  ],
    		 'Shiloh'				=> [ 13000, 10700 ],
			 'Second Bull Run'	=> [ 10000, 8000  ],
		     'Fredericksburg'		=> [ 12600, 5300  ],
		    },
	    	'plot.type'	=> 'barh',
    		color		=>	['blue', 'gray'], # colors match indices of data arrays
			label		=> ['North', 'South'], # colors match indices of data arrays
		    xlabel	=> 'Casualties',
	    	ylabel	=> 'Battle',
    		title		=> 'barh: hash of array'
		},
    	{ # 5th plot: barplot with groups
			data	=> {
		    	1942 => [ 109867,  310000, 7700000 ], # US, Japan, USSR
	    		1943 => [ 221111,  440000, 9000000 ],
    			1944 => [ 318584,  610000, 7000000 ],
				1945 => [ 318929, 1060000, 3000000 ],
		    },
	    	color		=> ['blue', 'pink', 'red'], # colors match indices of data arrays
    		label		=> ['USA', 'Japan', 'USSR'], # colors match indices of data arrays
			'log'		=> 1,
		    title		=> 'grouped bar: Casualties in WWII',
	    	ylabel	=> 'Casualties',
    		'plot.type'	=> 'bar'
		},	
	    { # nuclear weapons barplot
    		'plot.type'		=> 'bar',
			data => {
		    	'USA'				=> 5277, # FAS Estimate
	    		'Russia'			=> 5449, # FAS Estimate
    			'UK'				=> 225, # Consistent estimate
				'France'			=> 290, # Consistent estimate
			    'China'			=> 600, # FAS Estimate
    			'India'			=> 180, # FAS Estimate
				'Pakistan'		=> 130, # FAS Estimate
		    	'Israel'			=> 90, # FAS Estimate
	    		'North Korea'	=> 50, # FAS Estimate
    		},
			title		=> 'Simple hash for barchart with yerr',
		    xlabel	=> 'Country',
	    	yerr						=> {
    			'USA'				=> [15,29],
				'Russia'			=> [199,1000],
    			'UK'				=> [15,19],
				'France'			=> [19,29],
    			'China'			=> [200,159],
				'India'			=> [15,25],
			    'Pakistan'		=> [15,49],
		    	'Israel'			=> [90,50],
	    		'North Korea'	=> [10,20],
    		},
			ylabel	=> '# of Nuclear Warheads',
		    'log'						=> 'True', #	linewidth				=> 1,
	    }
    ],
    ncols	=> 3,
    nrows	=> 4
});

which produces the plot:

barplots

colors for each hash key defined by hash

plt({
	plots => [
		{
			color        => {
				A => 'red', B => 'green', C => 'blue'
			},
			data => {
				A => 1, B => 2, C => 3
			},
			'plot.type'   => 'bar'
		},
		{
			color        => {
				A => 'red', B => 'green', C => 'blue'
			},
			data => {
				A => 1, B => 2, C => 3
			},
			'plot.type'   => 'barh'
		},
	],
	ncols         => 2,
	'output.file' => '/tmp/key.colors.bar.svg',
});

which produces the plot

key colors bar

boxplot

Plot a hash of arrays as a series of boxplots

options

| Option | Description | Example | | -------- | ------- | ------- | |color | a single color for all plots | color => 'pink'| |colors| a hash, where each data point and color is a hash pair |colors => { A => 'orange', E => 'yellow', B => 'purple' },| | key.order| order that the keys in the entry hash will be plotted | key.order = ['A', 'E', 'B'] | | orientation| orientation of the plot, by default vertical| orientation = 'horizontal' | |showcaps| Show the caps on the ends of whiskers; default True | showcaps => 'False', | | showfliers |Show the outliers beyond the caps; default True | showfliers => 'False' | |showmeans | show means; default = True | showmeans => 'False' | |whiskers| show whiskers, default = 1| whiskers => 0,|

single, simple plot

my $x = generate_normal_dist( 100, 15, 3 * 10 );
my $y = generate_normal_dist( 85,  15, 3 * 10 );
my $z = generate_normal_dist( 106, 15, 3 * 10 );

single plots are simple

use Matplotlib::Simple 'barplot';
boxplot({
	'output.file' => 'output.images/single.boxplot.png',
	data              => {                                     # simple hash
		E => [ 55,    @{$x}, 160 ],
		B => [ @{$y}, 140 ],

		#		A => @a
	},
	title        => 'Single Box Plot: Specified Colors',
	colors       => { E => 'yellow', B => 'purple' },
	fh           => $fh,
	execute      => 0,
});

which makes the following image:

single boxplot

multiple plots

plt({
	'output.file' => 'output.images/boxplot.png',
	execute           => 0,
	fh                => $fh,
	plots             => [
		{
		    data => {
		        A => [ 55, @{$z} ],
		        E => [ @{$y} ],
		        B => [ 122, @{$z} ],
		    },
		    title       => 'Simple Boxplot',
		    ylabel      => 'ylabel',
		    xlabel      => 'label',
		    'plot.type' => 'boxplot',
		    suptitle    => 'Boxplot examples'
		},
		{
		    color => 'pink',
		    data  => {
		        A => [ 55, @{$z} ],
		        E => [ @{$y} ],
		        B => [ 122, @{$z} ],
		    },
		    title       => 'Specify single color',
		    ylabel      => 'ylabel',
		    xlabel      => 'label',
		    'plot.type' => 'boxplot'
		},
		{
		    colors => {
		        A => 'orange',
		        E => 'yellow',
		        B => 'purple'
		    },
		    data => {
		        A => [ 55, @{$z} ],
		        E => [ @{$y} ],
		        B => [ 122, @{$z} ],
		    },
		    title       => 'Specify set-specific color; showfliers = False',
		    ylabel      => 'ylabel',
		    xlabel      => 'label',
		    'plot.type' => 'boxplot',
		    showmeans   => 'True',
		    showfliers  => 'False',
		    set_figwidth => 12
		},
		{
		    colors => {
		        A => 'orange',
		        E => 'yellow',
		        B => 'purple'
		    },
		    data => {
		        A => [ 55, @{$z} ],
		        E => [ @{$y} ],
		        B => [ 122, @{$z} ],
		    },
		    title       => 'Specify set-specific color; showmeans = False',
		    ylabel      => 'ylabel',
		    xlabel      => 'label',
		    'plot.type' => 'boxplot',
		    showmeans   => 'False',
		},
		{
		    colors => {
		        A => 'orange',
		        E => 'yellow',
		        B => 'purple'
		    },
		    data => {
		        A => [ 55, @{$z} ],
		        E => [ @{$y} ],
		        B => [ 122, @{$z} ],
		    },
		    title       => 'Set-specific color; orientation = horizontal',
		    ylabel      => 'ylabel',
		    xlabel      => 'label',
		    orientation => 'horizontal',
		    'plot.type' => 'boxplot',
		},
		{
		    colors => {
		        A => 'orange',
		        E => 'yellow',
		        B => 'purple'
		    },
		    data => {
		        A => [ 55, @{$z} ],
		        E => [ @{$y} ],
		        B => [ 122, @{$z} ],
		    },
		    title       => 'Notch = True',
		    ylabel      => 'ylabel',
		    xlabel      => 'label',
		    notch       => 'True',
		    'plot.type' => 'boxplot',
		},
		{
		    colors => {
		        A => 'orange',
		        E => 'yellow',
		        B => 'purple'
		    },
		    data => {
		        A => [ 55, @{$z} ],
		        E => [ @{$y} ],
		        B => [ 122, @{$z} ],
		    },
		    title         => 'showcaps = False',
		    ylabel        => 'ylabel',
		    xlabel        => 'label',
		    showcaps      => 'False',
		    'plot.type'   => 'boxplot',
		    set_figheight => 12,
		},
	],
	ncols => 3,
	nrows => 3,
});

which makes the following plot:

boxplot

Colored Table

options

Single, simple plot

the bond dissociation energy table can be plotted:

# https://labs.chem.ucsb.edu/zakarian/armen/11---bonddissociationenergy.pdf and https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Chemical_Bonding/Fundamentals_of_Chemical_Bonding/Bond_Energies
my %bond_dissociation = (
	Br =>  {
	  Br =>  193
	},
	C  =>  {
		Br =>  276,	C  =>  347,	Cl =>  339,	F   => 485,	H  =>  413,	I  =>  240,
		N  =>  305,	O  =>  358,	S  =>  259
	},
	Cl =>  {
		Br =>  218,	Cl =>  239
	},
	F =>   {
		I => 280, Br =>  237, Cl  => 253, F   => 154
	},
	H  =>  {
		Br =>  363,	Cl =>  427,	F  =>  565,	H   => 432,	I   => 295
	},
	I  =>  {
		Br  => 175,	Cl =>  208,	I  =>  149
	},
	N  =>  {
		Br =>  243,	Cl  => 200,	F   => 272,	H  =>  391,	N  =>  160, O  =>  201
	},
	O =>   {
		Cl =>  203, F  =>  190,	H  =>  467,	I  =>  234,	O  =>  146
	},
	S  =>  {
		Br => 218,	Cl => 253,	F  => 327,	H  => 347,	S  => 266
	},
	Si => {
		C  => 360, H  => 393, O  => 452,	Si => 340
	}
);

and the plot itself:

colored_table({
	'cblabel'     => 'kJ/mol',
	'col.labels'  => ['H', 'F', 'Cl', 'Br', 'I'],
	data          => \%bond_dissociation,
	execute       => 0,
	fh            => $fh,
	mirror        => 1,
	'output.file' => 'output.images/single.tab.png',
	'row.labels'  => ['H', 'F', 'Cl', 'Br', 'I'],
	'show.numbers'=> 1,
	set_title     => 'Bond Dissociation Energy'
});

which makes the following image:

single tab

Multiple Plots

plt({
	'output.file' => 'output.images/tab.multiple.png',
	execute       => 0,
	fh            => $fh,
	plots         => [
		{
			data          => \%bond_dissociation,
			'output.file' => '/tmp/single.bonds.svg',
			'plot.type'   => 'colored_table',
			set_title     => 'No other options'
		},
		{
			data          => \%bond_dissociation,
			cblabel       => 'Average Dissociation Energy (kJ/mol)',
			'col.labels'  => ['H', 'C', 'N', 'O', 'F', 'Si', 'S', 'Cl', 'Br', 'I'],
			mirror        => 1,
			'output.file' => '/tmp/single.bonds.svg',
			'plot.type'   => 'colored_table',
			'row.labels'  => ['H', 'C', 'N', 'O', 'F', 'Si', 'S', 'Cl', 'Br', 'I'],
			'show.numbers'=> 1,
			set_title     => 'Showing numbers and mirror with defined order'
		},
		{
			data          => \%bond_dissociation,
			cblabel       => 'Average Dissociation Energy (kJ/mol)',
			'col.labels'  => ['H', 'C', 'N', 'O', 'F', 'Si', 'S', 'Cl', 'Br', 'I'],
			mirror        => 1,
			'output.file' => '/tmp/single.bonds.svg',
			'plot.type'   => 'colored_table',
			'row.labels'  => ['H', 'C', 'N', 'O', 'F', 'Si', 'S', 'Cl', 'Br', 'I'],
			'show.numbers'=> 1,
			set_title     => 'Set undefined color to white',
			'undef.color' => 'white'
		}
	],
	ncols         => 3,
	set_figwidth  => 14,
	suptitle      => 'Colored Table options'
});

which makes the following plot:

tab multiple

hexbin

Plot a hash of arrays as a hexbin see https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.hexbin.html

options

| Option | Description | Example | | -------- | ------- | ------- | cb_logscale | colorbar log scale from matplotlib.colors import LogNorm | default 0, any value > 0 enables | |cmap| The Colormap instance or registered colormap name used to map scalar data to colors | default gist_rainbow | |key.order| define the keys in an order (an array reference)|'key.order' => ['X-rays', 'Yak Butter'], | marginals | integer, by default off = 0 | marginals => 1 | | mincnt | int >= 0, default: None; If not None, only display cells with at least mincnt number of points in the cell. | mincnt => 2| | vmax | The normalization method used to scale scalar data to the [0, 1] range before mapping to colors using cmap | 'asinh', 'function', 'functionlog', 'linear', 'log', 'logit', 'symlog' default linear | | vmin | The normalization method used to scale scalar data to the [0, 1] range before mapping to colors using cmap | 'asinh', 'function', 'functionlog', 'linear', 'log', 'logit', 'symlog' default linear | | xbins | integer that accesses horizontal gridsize | default is 15 | | xscale.hexbin | 'linear', 'log'}, default: 'linear': Use a linear or log10 scale on the horizontal axis | 'xscale.hexbin' => 'log'| | ybins | integer that accesses vertical gridsize | default is 15 | | yscale.hexbin | 'linear', 'log'}, default: 'linear': Use a linear or log10 scale on the vertical axis | 'yscale.hexbin' => 'log'|

single, simple plot

plt({
	data	=> {
		E	=> generate_normal_dist(100, 15, 3*210),
		B	=> generate_normal_dist(85, 15, 3*210)
	},
	'output.file'	=> 'output.images/single.hexbin.png',
	'plot.type'	=> 'hexbin',
	set_figwidth => 12,
	title			=> 'Simple Hexbin',
});

which makes the following plot: single hexbin

multiple plots

plt({
	fh => $fh,
	execute           => 0,
	'output.file' => 'output.images/hexbin.png',
	plots             => [
		{
			data => {
			E => @e,
			B => @b
			},
			'plot.type'  => 'hexbin',
			title        => 'Simple Hexbin',
		},
		{
		    data => {
		        E => @e,
		        B => @b
		    },
		    'plot.type' => 'hexbin',
		    title       => 'colorbar logscale',
		    cb_logscale => 1
		},
		{
		    cmap => 'jet',
		    data => {
		        E => @e,
		        B => @b
		    },
		    'plot.type'  => 'hexbin',
		    title        => 'cmap is jet',
		    xlabel       => 'xlabel',
		},
		 {
		    data => {
		        E => @e,
		        B => @b
		    },
		    'key.order'  => ['E', 'B'],
		    'plot.type'  => 'hexbin',
		    title        => 'Switch axes with key.order',
		},
		 {
		    data => {
		        E => @e,
		        B => @b
		    },
		    'plot.type'  => 'hexbin',
		    title        => 'vmax set to 25',
		    vmax         => 25
		},
		 {
		    data => {
		        E => @e,
		        B => @b
		    },
		    'plot.type'  => 'hexbin',
		    title        => 'vmin set to -4',
		    vmin         => -4
		},
		{
		    data => {
		        E => @e,
		        B => @b
		    },
		    'plot.type'  => 'hexbin',
		    title        => 'mincnt set to 7',
		    mincnt       => 7
		},
		{
		    data => {
		        E => @e,
		        B => @b
		    },
		    'plot.type'  => 'hexbin',
		    title        => 'xbins set to 9',
		    xbins        => 9
		},
		{
		    data => {
		        E => @e,
		        B => @b
		    },
		    'plot.type'  => 'hexbin',
		    title        => 'ybins set to 9',
		    ybins        => 9
		},
		{
		    data => {
		        E => @e,
		        B => @b
		    },
		    'plot.type'  => 'hexbin',
		    title        => 'marginals = 1',
		    marginals    => 1
		},
		{
		    data => {
		        E => @e,
		        B => @b
		    },
		    'plot.type'  => 'hexbin',
		    title        => 'xscale.hexbin = 1',
		    'xscale.hexbin' => 'log'
		},
		{
		    data => {
		        E => @e,
		        B => @b
		    },
		    'plot.type'  => 'hexbin',
		    title        => 'yscale.hexbin = 1',
		    'yscale.hexbin' => 'log'
		},
	],
	ncols        => 4,
	nrows        => 3,
	scale        => 5,
	suptitle     => 'Various Changes to Standard Hexbin: All data is the same'
});

which produces the following image: hexbin

hist

Plot a hash of arrays as a series of histograms

options

| Option | Description | Example | | -------- | ------- | ------- | |alpha | default 0.5; same for all sets| | |bins | # nt or sequence or str, default: :rc:hist.binsIf bins is an integer, it defines the number of equal-width bins in the range. If bins is a sequence, it defines the bin edges, including the left edge of the first bin and the right edge of the last bin; in this case, bins may be unequally spaced. All but the last (righthand-most) bin is half-open| |color | a hash, where keys are the keys in data, and values are colors | X => 'blue'| |log| if set to > 1, the y-axis will be logarithmic | |orientation| {'vertical', 'horizontal'}, default: 'vertical'|

single, simple plot

as of version 0.26, single arrays can be given to hist instead of a hash, simplifying the call:

hist({
 	data          => [0..9],
	'output.file' => '/tmp/hist.arr.svg',
});

for slightly more complex data sets, hashes are taken:

use Matplotlib::Simple 'hist';

my @e = generate_normal_dist( 100, 15, 3 * 200 );
my @b = generate_normal_dist( 85,  15, 3 * 200 );
my @a = generate_normal_dist( 105, 15, 3 * 200 );

hist({
	fh => $fh,
	execute           => 0,
	'output.file' => 'output.images/single.hist.png',
	data              => {
    	E => @e,
    	B => @b,
    	A => @a,
	}
});

which makes the following simple plot:

single hist

multiple plots

plt({
	fh => $fh,
	execute           => 0,
	'output.file' => 'output.images/histogram.png',
   set_figwidth => 15,
   suptitle          => 'hist Examples',
	plots             => [
		{ # 1st subplot
		    data => {
		        E => @e,
		        B => @b,
		        A => @a,
		    },
		    'plot.type' => 'hist',
		    alpha       => 0.25,
		    bins        => 50,
		    title       => 'alpha = 0.25',
		    color       => {
		        B => 'Black',
		        E => 'Orange',
		        A => 'Yellow',
		    },
		    scatter => '['
		      . join( ',', 22 .. 44 ) . '],['  # x coords
		      . join( ',', 22 .. 44 )          # y coords
		      . '], label = "scatter"',
		    xlabel   => 'Value',
		    ylabel   => 'Frequency',
		},
		{ # 2nd subplot
		    data => {
				E => @e,
				B => @b,
				A => @a,
		    },
		    'plot.type' => 'hist',
		    alpha       => 0.75,
		    bins        => 50,
		    title       => 'alpha = 0.75',
		    color       => {
		        B => 'Black',
		        E => 'Orange',
		        A => 'Yellow',
		    },
		    xlabel   => 'Value',
		    ylabel   => 'Frequency',
		},
		{ # 3rd subplot
			add               => [ # add secondary plots/graphs/methods
			{ # 1st additional plot/graph
				data              => {
					'Gaussian'       => [
						[40..150],
						[map {150 * exp(-0.5*($_-100)**2)} 40..150]
					]
				},
				'plot.type' => 'plot',
				'set.options' => {
					'Gaussian' =>  'color = "red", linestyle = "dashed"'
				}
			}
			],
		   data => {
		        E => @e,
		        B => @b,
		        A => @a,
		    },
		    'plot.type' => 'hist',
		    alpha       => 0.75,
		    bins        => {
		        A => 10,
		        B => 25,
		        E => 50
		    },
		    title => 'Varying # of bins',
		    color => {
		        B => 'Black',
		        E => 'Orange',
		        A => 'Yellow',
		    },
		    xlabel       => 'Value',
		    ylabel       => 'Frequency',
		},
		{# 4th subplot
		    data => {
		        E => @e,
		        B => @b,
		        A => @a,
		    },
		    'plot.type' => 'hist',
		    alpha       => 0.75,
		    color       => {
		        B => 'Black',
		        E => 'Orange',
		        A => 'Yellow',
		    },
		    orientation  => 'horizontal',    # assign x and y labels smartly
		    title        => 'Horizontal orientation',
		    ylabel       => 'Value',
		    xlabel       => 'Frequency',                #				'log'					=> 1,
		},
	],
	ncols => 3,
	nrows => 2,
});
histogram

hist2d

Make a 2-D histogram from a hash of arrays

single, simple plot

plt({
	'output.file' => 'output.images/single.hist2d.png',
	data              => {
		E => @e,
		B => @b
	},
	'plot.type'  => 'hist2d',
	title        => 'title',
	execute      => 0,
	fh => $fh,
});

makes the following image:

single hist2d

the range for the density min and max is reported to stdout

options

| Option | Description | Example | | -------- | ------- | ------- | |cb_logscale| make the colorbar log-scale | cb_logscale => 1 | |cmap| color map for coloring # "gist_rainbow" by default | | |'cmax', cmin| All bins that has count < cmin or > cmax will not be displayed| | 'density'| density : bool, default: False| | 'key.order'| define the keys in an order (an array reference) | 'logscale' | # logscale, an array of axes that will get log scale |'show.colorbar'| self-evident, 0 or 1 | show.colorbar => 1| |'vmax'| When using scalar data and no explicit norm, vmin and vmax define the data range that the colormap cover | |'vmin' | # When using scalar data and no explicit norm, vmin and vmax define the data range that the colormap cover | |'xbins'| # default 15 |'xmin', 'xmax',| |'ymin', 'ymax',| |'ybins' | default 15 |

multiple plots

plt({
	fh => $fh,
	execute           => 1,
	ncols             => 3,
	nrows             => 3,
	suptitle          => 'Types of hist2d plots: all of the data is identical',
	plots => [
		{
			data => {
			X => $x,    # x-axis
			Y => $y,    # y-axis
			},
			'plot.type' => 'hist2d',
			title       => 'Simple hist2d',
		},
		{
			data => {
				X => $x,    # x-axis
				Y => $y,    # y-axis
			},
			'plot.type' => 'hist2d',
			title       => 'cmap = terrain',
			cmap        => 'terrain'
		},
		{
			cmap => 'ocean',
			data => {
				X => $x,    # x-axis
				Y => $y,    # y-axis
			},
			'plot.type' => 'hist2d',
			title => 'cmap = ocean and set colorbar range with vmin/vmax',
			set_figwidth => 15,
			vmin         => -2,
			vmax         => 14
		},
		{
			data => {
				X => $x,    # x-axis
				Y => $y,    # y-axis
			},
			'plot.type' => 'hist2d',
			title       => 'density = True',
			cmap        => 'terrain',
			density     => 'True'
		},
		{
			data => {
				X => $x,    # x-axis
				Y => $y,    # y-axis
			},
			'plot.type' => 'hist2d',
			title       => 'key.order flips axes',
			cmap        => 'terrain',
			'key.order' => [ 'Y', 'X' ]
		},
		{
			cb_logscale => 1,
			data => {
				X => $x,    # x-axis
				Y => $y,    # y-axis
			},
			'plot.type' => 'hist2d',
			title       => 'cb_logscale = 1',
		},
		{
			cb_logscale => 1,
			data => {
				X => $x,    # x-axis
				Y => $y,    # y-axis
			},
			'plot.type' => 'hist2d',
			title       => 'cb_logscale = 1 with vmax set',
			vmax        => 2.1,
			vmin        => 1
		},
		{
			data => {
				X => $x,    # x-axis
				Y => $y,    # y-axis
			},
			'plot.type'     => 'hist2d',
			'show.colorbar' => 0,
			title           => 'no colorbar',
		},
		{
			data => {
				X => $x,    # x-axis
				Y => $y,    # y-axis
			},
			'plot.type'     => 'hist2d',
			title           => 'xbins = 9',
			xbins           => 9
		},
	],
	'output.file' => 'output.images/hist2d.png',
});

makes the following image:

hist2d

imshow

Plot 2D array of numbers as an image

options

| Option | Description | Example | | -------- | ------- | ------- |cblabel| colorbar label | cblabel => 'sin(x) * cos(x)', |cbdrawedges |draw edges for colorbar | | |cblocation | 'left', 'right', 'top', 'bottom'| cblocation => 'left',| |cborientation| None, or 'vertical', 'horizontal' | |cmap| # The Colormap instance or registered colormap name used to map scalar data to colors.| |vmax| float | |vmin| float |

single, simple plot

my @imshow_data;
foreach my $i (0..360) {
	foreach my $j (0..360) {
		push @{ $imshow_data[$i] }, sin($i * $pi/180)*cos($j * $pi/180);
	}
}
plt({
	data              => \@imshow_data,
	execute           => 0,
   fh => $fh,
	'output.file' => 'output.images/imshow.single.png',
	'plot.type'       => 'imshow',
	set_xlim          => '0, ' . scalar @imshow_data,
	set_ylim          => '0, ' . scalar @imshow_data,
});

which makes the following image:

imshow single

multiple plots

plt({
	plots  => [
		{
			data => \@imshow_data,
			'plot.type'       => 'imshow',
			set_xlim          => '0, ' . scalar @imshow_data,
			set_ylim          => '0, ' . scalar @imshow_data,
			title             => 'basic',
		},
		{
			cblabel           => 'sin(x) * cos(x)',
			data => \@imshow_data,
			'plot.type'       => 'imshow',
			set_xlim          => '0, ' . scalar @imshow_data,
			set_ylim          => '0, ' . scalar @imshow_data,
			title             => 'cblabel',
		},
		{
			cblabel           => 'sin(x) * cos(x)',
			cblocation        => 'left',
			data              => \@imshow_data,
			'plot.type'       => 'imshow',
			set_xlim          => '0, ' . scalar @imshow_data,
			set_ylim          => '0, ' . scalar @imshow_data,
			title             => 'cblocation = left',
		},
		{
			cblabel           => 'sin(x) * cos(x)',
			data              => \@imshow_data,
			add               => [ # add secondary plots
			{ # 1st additional plot
				data              => {
					'sin(x)'       => [
						[0..360],
						[map {180 + 180*sin($_ * $pi/180)} 0..360]
					],
					'cos(x)'       => [
						[0..360],
						[map {180 + 180*cos($_ * $pi/180)} 0..360]
					],
				},
				'plot.type' => 'plot',
				'set.options' => {
					'sin(x)'	=>  'color = "red", linestyle = "dashed"',
					'cos(x)'	=>  'color = "blue", linestyle = "dashed"',
				}
			}
			],
			'plot.type'       => 'imshow',
			set_xlim          => '0, ' . scalar @imshow_data,
			set_ylim          => '0, ' . scalar @imshow_data,
			title             => 'auxiliary plots',
		},
	],
	execute         => 0,
  fh              => $fh,
	'output.file'   => 'output.images/imshow.multiple.png',
	ncols           => 2,
	nrows           => 2,
	set_figheight   => 6*3,# 4.8
	set_figwidth    => 6*4 # 6.4
});

which makes the following image:

imshow multiple

Secondary Structure Prediction (DSSP)

Sometimes strings instead of numbers can be entered into a 2-D array, one example is protein secondary structure. Protein secondary structure can be plotted thus, with a key in stringmap to show which strings become which integers in a minimal working example:

plt({
	cbpad       => 0.01,          # default 0.05 is too big
	data        => [              # imshow gets a 2D array
		[' ', ' ', ' ', ' ', 'G'], # bottom
		['S', 'I', 'T', 'E', 'H'], # top
	],
	'plot.type' => 'imshow',
	stringmap   => {
		'H' => 'Alpha helix',
		'B' => 'Residue in isolated β-bridge',
		'E' => 'Extended strand, participates in β ladder',
		'G' => '3-helix (3/10 helix)',
		'I' => '5 helix (pi helix)',
		'T' => 'hydrogen bonded turn',
		'S' => 'bend',
		' ' => 'Loops and irregular elements'
	},
	'output.file' => 'output.images/dssp.single.png',
	scalex        => 2.4,
	set_ylim      => '0, 1',
	title         => 'Dictionary of Secondary Structure in Proteins (DSSP)',
	xlabel        => 'xlabel',
	ylabel        => 'ylabel'
});
dssp single

or for multiple plots, where the colorbar can be spread across multiple plots now:

plt({
	cbpad       => 0.01,          # default 0.05 is too big
	plots       => [
		{ # 1st plot
			data 	=> [
				[' ', ' ', ' ', ' ', 'G'], # bottom
				['S', 'I', 'T', 'E', 'H'], # top
			],
			'plot.type' => 'imshow',
			set_xticklabels=> '[]', # remove x-axis labels
			set_ylim    => '0, 1',
			stringmap   => {
				'H' => 'Alpha helix',
				'B' => 'Residue in isolated β-bridge',
				'E' => 'Extended strand, participates in β ladder',
				'G' => '3-helix (3/10 helix)',
				'I' => '5 helix (pi helix)',
				'T' => 'hydrogen bonded turn',
				'S' => 'bend',
				' ' => 'Loops and irregular elements'
			},
			title         => 'top plot',
			ylabel        => 'ylabel'
		},
		{ # 2nd plot
			data 	=> [
				[' ', ' ', ' ', ' ', 'G'], # bottom
				['S', 'I', 'T', 'E', 'H'], # top
			],
			'plot.type' => 'imshow',
			set_ylim    => '0, 1',
			stringmap   => {
				'H' => 'Alpha helix',
				'B' => 'Residue in isolated β-bridge',
				'E' => 'Extended strand, participates in β ladder',
				'G' => '3-helix (3/10 helix)',
				'I' => '5 helix (pi helix)',
				'T' => 'hydrogen bonded turn',
				'S' => 'bend',
				' ' => 'Loops and irregular elements'
			},
			title         => 'bottom plot',
			xlabel        => 'xlabel',
			ylabel        => 'ylabel'
		}
	],
	nrows             => 2,
	'output.file'     => 'output.images/dssp.multiple.png',
	scalex            => 2.4,
	'shared.colorbar' => [0,1], # plots 0 and 1 share a colorbar
	suptitle          => 'Dictionary of Secondary Structure in Proteins (DSSP)',
});

which makes the following plot:

dssp multiple

pie

options

single, simple plot

plt({
	'output.file' => 'output.images/single.pie.png',
	data              => {                                 # simple hash
		Fri => 76,
		Mon => 73,
		Sat => 26,
		Sun => 11,
		Thu => 94,
		Tue => 93,
		Wed => 77
	},
	'plot.type'  => 'pie',
	title        => 'Single Simple Pie',
	fh           => $fh,
	execute      => 0,
});

which makes the image:

single pie

multiple plots

plt({
	'output.file' => 'output.images/pie.png',
	plots             => [
		{
		    data => {
		        'Russian' => 106_000_000,    # Primarily European Russia
		        'German'  =>
		          95_000_000,    # Germany, Austria, Switzerland, etc.
		        'English' => 70_000_000,      # UK, Ireland, etc.
		        'French' => 66_000_000, # France, Belgium, Switzerland, etc.
		        'Italian'   => 59_000_000,    # Italy, Switzerland, etc.
		        'Spanish'   => 45_000_000,    # Spain
		        'Polish'    => 38_000_000,    # Poland
		        'Ukrainian' => 32_000_000,    # Ukraine
		        'Romanian'  => 24_000_000,    # Romania, Moldova
		        'Dutch'     => 22_000_000     # Netherlands, Belgium
		    },
		    'plot.type' => 'pie',
		    title       => 'Top Languages in Europe',
		    suptitle    => 'Pie in subplots',
		},
		{
		    data => {
		        'Russian' => 106_000_000,     # Primarily European Russia
		        'German'  =>
		          95_000_000,    # Germany, Austria, Switzerland, etc.
		        'English' => 70_000_000,      # UK, Ireland, etc.
		        'French' => 66_000_000, # France, Belgium, Switzerland, etc.
		        'Italian'   => 59_000_000,    # Italy, Switzerland, etc.
		        'Spanish'   => 45_000_000,    # Spain
		        'Polish'    => 38_000_000,    # Poland
		        'Ukrainian' => 32_000_000,    # Ukraine
		        'Romanian'  => 24_000_000,    # Romania, Moldova
		        'Dutch'     => 22_000_000     # Netherlands, Belgium
		    },
		    'plot.type' => 'pie',
		    title       => 'Top Languages in Europe',
		    autopct     => '%1.1f%%',
		},
		{
		    data => {
		        'United States'  => 86,
		        'United Kingdom' => 33,
		        'Germany'        => 29,
		        'France'         => 10,
		        'Japan'          => 7,
		        'Israel'         => 6,
		    },
		    title         => 'Chem. Nobels: swap text positions',
		    'plot.type'   => 'pie',
		    autopct       => '%1.1f%%',
		    pctdistance   => 1.25,
		    labeldistance => 0.6,
		}
	],
	fh => $fh,
	execute      => 0,
   set_figwidth  => 12,
	ncols        => 3,
});
pie

plot

plot either a hash of arrays or an array of arrays

single, simple

data can be given as a hash, where the hash key is the label:

plt({
	fh => $fh,
	execute           => 0,
	'output.file' => 'output.images/plot.single.png',
	data              => {
		'sin(x)' => [
		    [@x],                     # x
		    [ map { sin($_) } @x ]    # y
		],
		'cos(x)' => [
		    [@x],                     # x
		    [ map { cos($_) } @x ]    # y
		],
	},
	'plot.type' => 'plot',
	title       => 'simple plot',
	set_xticks  =>
	"[-2 * $pi, -3 * $pi / 2, -$pi, -$pi / 2, 0, $pi / 2, $pi, 3 * $pi / 2, 2 * $pi"
	 . '], [r\'$-2\pi$\', r\'$-3\pi/2$\', r\'$-\pi$\', r\'$-\pi/2$\', r\'$0$\', r\'$\pi/2$\', r\'$\pi$\', r\'$3\pi/2$\', r\'$2\pi$\']',
	'set.options' => {    # set options overrides global settings
		'sin(x)' => 'color="blue", linewidth=2',
		'cos(x)' => 'color="red",  linewidth=2'
	}
});

or as an array of arrays:

plt({
	fh => $fh,
	execute           => 0,
	'output.file' => 'output.images/plot.single.arr.png',
	data              => [
		[
			[@x],                     # x
			[ map { sin($_) } @x ]    # y
		],
		[
		 	[@x],                     # x
		 	[ map { cos($_) } @x ]    # y
		],
	],
	'plot.type' => 'plot',
	title       => 'simple plot',
	set_xticks  =>
	"[-2 * $pi, -3 * $pi / 2, -$pi, -$pi / 2, 0, $pi / 2, $pi, 3 * $pi / 2, 2 * $pi"
	 . '], [r\'$-2\pi$\', r\'$-3\pi/2$\', r\'$-\pi$\', r\'$-\pi/2$\', r\'$0$\', r\'$\pi/2$\', r\'$\pi$\', r\'$3\pi/2$\', r\'$2\pi$\']',
	'set.options' => [    # set options overrides global settings; indices match data array
		'color="blue", linewidth=2, label = "sin(x)"', # labels aren't added automatically when using array here
		'color="red",  linewidth=2, label = "cos(x)"'
	],
});

both of which make the following "plot" plot:

plot single

multiple sub-plots

which makes

my $epsilon = 10**-7;
my (%set_opt, %d);
my $i = 0;
foreach my $interval (
	[-2*$pi, -$pi],
	[-$pi, 0],
	[0, $pi],
	[$pi, 2*$pi]
) {
	my @th = linspace($interval->[0] + $epsilon, $interval->[1] - $epsilon, 99, 0);
	@{ $d{csc}{$i}[0] } = @th;
	@{ $d{csc}{$i}[1] } = map { 1/sin($_) } @th;
	@{ $d{cot}{$i}[0] } = @th;
	@{ $d{cot}{$i}[1] } = map { cos($_)/sin($_) } @th;
	if ($i == 0) {
		$set_opt{csc}{$i} = 'color = "red", label = "csc(θ)"';
		$set_opt{cot}{$i} = 'color = "violet", label = "cot(θ)"';
	} else {
		$set_opt{csc}{$i} = 'color = "red"';
		$set_opt{cot}{$i} = 'color = "violet"';
	}
	$i++;
}
$i = 0;
foreach my $interval (
	[-2 * $pi, -1.5 * $pi],
	[-1.5*$pi, -0.5*$pi],
	[-0.5*$pi, 0.5 * $pi],
	[0.5 * $pi, 1.5 * $pi],
	[1.5 * $pi, 2 * $pi]
) {
	my @th = linspace($interval->[0] + $epsilon, $interval->[1] - $epsilon, 99, 0);
	@{ $d{sec}{$i}[0] } = @th;
	@{ $d{sec}{$i}[1] } = map { 1/cos($_) } @th;
	if ($i == 0) {
		$set_opt{sec}{$i} = 'color = "blue", label = "sec(θ)"';
		$set_opt{tan}{$i} = 'color = "green", label = "tan(θ)"';
	} else {
		$set_opt{sec}{$i} = 'color = "blue"';
		$set_opt{tan}{$i} = 'color = "green"';
	}
	@{ $d{tan}{$i}[0] } = @th;
	@{ $d{tan}{$i}[1] } = map { sin($_)/cos($_) } @th;
	$i++;
}
mkdir 'svg' unless -d 'svg';
my $xticks = "[-2 * $pi, -3 * $pi / 2, -$pi, -$pi / 2, 0, $pi / 2, $pi, 3 * $pi / 2, 2 * $pi"
		. '], [r\'$-2\pi$\', r\'$-3\pi/2$\', r\'$-\pi$\', r\'$-\pi/2$\', r\'$0$\', r\'$\pi/2$\', r\'$\pi$\', r\'$3\pi/2$\', r\'$2\pi$\']';
my ($min, $max) = (-9,9);
plt({
	fh => $fh,
	execute           => 0,
	'output.file' => 'output.images/plots.png',
	plots         => [
	{ # sin
		data          => {
			'sin(θ)' => [
				[@x],
				[map {sin($_)} @x]
			]
		},
		'plot.type'   => 'plot',
		'set.options' => {
			'sin(θ)' => 'color = "orange"'
		},
		set_xticks    => $xticks,
		set_xlim      => "-2*$pi, 2*$pi",
		xlabel        => 'θ',
		ylabel        => 'sin(θ)',
	},
	{ # sin
		data          => {
			'cos(θ)' => [
				[@x],
				[map {cos($_)} @x]
			]
		},
		'plot.type'   => 'plot',
		'set.options' => {
			'cos(θ)' => 'color = "black"'
		},
		set_xticks    => $xticks,
		set_xlim      => "-2*$pi, 2*$pi",
		xlabel        => 'θ',
		ylabel        => 'cos(θ)',
	},
	{ # csc
		data          => $d{csc},
		'plot.type'   => 'plot',
		'set.options' => $set_opt{csc},
		set_xticks    => $xticks,
		set_xlim      => "-2*$pi, 2*$pi",
		set_ylim      => "$min,$max",
		'show.legend' => 0,
		vlines        => [ # asymptotes
			"-2*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
			"-$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
			"0, $min, $max, color = 'gray', linestyle = 'dashed'",
			"$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
			"2*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
		],
		xlabel        => 'θ',
		ylabel        => 'csc(θ)',
	},
	{ # sec
		data          => $d{sec},
		'plot.type'   => 'plot',
		'set.options' => $set_opt{sec},
		set_xticks    => $xticks,
		set_xlim      => "-2*$pi, 2*$pi",
		set_ylim      => "$min,$max",
		'show.legend' => 0,
		vlines        => [ # asymptotes
			"-1.5*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
			"-.5*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
			".5*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
			"1.5*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
#			"2*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
		],
		xlabel        => 'θ',
		ylabel        => 'sec(θ)',
	},
		{ # csc
		data          => $d{cot},
		'plot.type'   => 'plot',
		'set.options' => $set_opt{cot},
		set_xticks    => $xticks,
		set_xlim      => "-2*$pi, 2*$pi",
		set_ylim      => "$min,$max",
		'show.legend' => 0,
		vlines        => [ # asymptotes
			"-2*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
			"-$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
			"0, $min, $max, color = 'gray', linestyle = 'dashed'",
			"$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
			"2*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
		],
		xlabel        => 'θ',
		ylabel        => 'cot(θ)',
	},
	{ # sec
		data          => $d{tan},
		'plot.type'   => 'plot',
		'set.options' => $set_opt{tan},
		set_xticks    => $xticks,
		set_xlim      => "-2*$pi, 2*$pi",
		set_ylim      => "$min,$max",
		'show.legend' => 0,
		vlines        => [ # asymptotes
			"-1.5*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
			"-.5*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
			".5*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
			"1.5*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
#			"2*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
		],
		xlabel        => 'θ',
		ylabel        => 'tan(θ)',
	},
	], # end
	ncols        => 2,
	nrows        => 3,
	set_figwidth => 8,
	suptitle     => 'Basic Trigonometric Functions'
});
plots

scatter

single, simple plot

scatter({
	fh            => $fh,
	data          => {
		X => [@x],
		Y => [map {sin($_)} @x]
	},
	execute       => 0,
	'output.file' => 'output.images/single.scatter.png',
});

makes the following image:

single scatter

options

multiple plots

plt({
	fh => $fh,
	'output.file' => 'output.images/scatterplots.png',
	execute           => 0,
	nrows             => 2,
	ncols             => 3,
	set_figheight     => 8,
	set_figwidth      => 16,
	suptitle          => 'Scatterplot Examples',            # applies to all
	plots             => [
		{    # single-set scatter; no label
			data => {
				X => @e,    # x-axis
				Y => @b,    # y-axis
				Z => @a     # color
			},
			title     => '"Single Set Scatterplot: Random Distributions"',
			color_key => 'Z',
			'set.options' => 'marker = "v"'
			, # arguments to ax.scatter: there's only 1 set, so "set.options" is a scalar
			text        => [ '100, 100, "text1"', '100, 100, "text2"', ],
			'plot.type' => 'scatter',
		},
		{     # multiple-set scatter, labels are "X" and "Y"
			data => {
				X => {    # 1st data set; label is "X"
					A => @a,    # x-axis
					B => @b,    # y-axis
				},
				W => {    # 2nd data set; label is "Y"
					A => generate_normal_dist( 100, 15, 210 ),    # x-axis
					B => generate_normal_dist( 100, 15, 210 ),    # y-axis
				}
			},
			'plot.type'   => 'scatter',
			title         => 'Multiple Set Scatterplot',
			'set.options' =>
			{    # arguments to ax.scatter, for each set in data
			  X => 'marker = ".", color = "red"',
			  W => 'marker = "d", color = "green"'
			},
		},
		{          # multiple-set scatter, labels are "X" and "Y"
			data => {    # 8th plot,
				X => {    # 1st data set; label is "X"
					A => @e,    # x-axis
					B => @b,    # y-axis
					C => @a,    # color
				},
				Y => {    # 2nd data set; label is "Y"
					A => generate_normal_dist( 100, 15, 210 ),    # x-axis
					B => generate_normal_dist( 100, 15, 210 ),    # y-axis
					C => generate_normal_dist( 100, 15, 210 ),    # color
				},
			},
			'plot.type'   => 'scatter',
			title         => 'Multiple Set Scatter w/ colorbar',
			'set.options' => {    # arguments to ax.scatter, for each set in data
				X => 'marker = "."',    # diamond
				Y => 'marker = "d"'     # diamond
			},
			color_key => 'Z',
		}
	]
});

which makes the following figure:

scatterplots

violin

plot a hash of array refs as violins

options

| Option | Description | Example | | -------- | ------- | ------- |color| # a hash, where keys are the keys in data, and values are colors, e.g. X => 'blue' |colors| match sets | colors => { E => 'yellow', B => 'purple', A => 'green' }| |key.order| determine key order display on x-axis| |log| # if set to > 1, the y-axis will be logarithmic |orientation|'vertical', 'horizontal'}, default: 'vertical'|

single, simple plot

plt({
	'output.file' => 'output.images/single.violinplot.png',
	data              => {                                     # simple hash
		A => [ 55, @{$z} ],
		E => [ @{$y} ],
		B => [ 122, @{$z} ],
	},
	'plot.type'  => 'violinplot',
	title        => 'Single Violin Plot: Specified Colors',
	colors       => { E => 'yellow', B => 'purple', A => 'green' },
	fh => $fh,
	execute      => 0,
});

which makes:

single violinplot

multiple plots

plt({
	fh                => $fh,
	execute           => 0,
	'output.file'     => 'output.images/violin.png',
	plots             => [
		{
		    data => {
		        E => @e,
		        B => @b
		    },
		    'plot.type'  => 'violinplot',
		    title        => 'Basic',
		    xlabel       => 'xlabel',
		    set_figwidth => 12,
		    suptitle     => 'Violinplot'
		},
		{
		    data => {
		        E => @e,
		        B => @b
		    },
		    'plot.type' => 'violinplot',
		    color       => 'red',
		    title       => 'Set Same Color for All',
		},
		{
		    data => {
		        E => @e,
		        B => @b
		    },
		    'plot.type' => 'violinplot',
		    colors      => {
		        E => 'yellow',
		        B => 'black'
		    },
		    title => 'Color by Key',
		},
		{
		    data => {
		        E => @e,
		        B => @b
		    },
		    orientation => 'horizontal',
		    'plot.type' => 'violinplot',
		    colors      => {
		        E => 'yellow',
		        B => 'black'
		    },
		    title => 'Horizontal orientation',
		},
		{
		    data => {
		        E => @e,
		        B => @b
		    },
		    whiskers    => 0,
		    'plot.type' => 'violinplot',
		    colors      => {
		        E => 'yellow',
		        B => 'black'
		    },
		    title => 'Whiskers off',
		},
	],
	ncols => 3,
	nrows => 2,
});
violin

wide

options

single, simple plot

multiple plots

Advanced

Notes in Files

all files that can have notes with them, give notes about how the file was written. For example, SVG files have the following:

<dc:title>made/written by /mnt/ceph/dcondon/ui/gromacs/tut/dup.2puy/1.plot.gromacs.pl called using "plot" in /mnt/ceph/dcondon/perl5/perlbrew/perls/perl-5.42.0/lib/site_perl/5.42.0/x86_64-linux/Matplotlib/Simple.pm</dc:title>`

Speed

To improve speed, all data can be written into a single temp python3 file thus:

use File::Temp;
my $fh = File::Temp->new( DIR => '/tmp', SUFFIX => '.py', UNLINK => 0 );

all files will be written to $fh->filename; be sure to put execute => 0 unless you want the file to be run, which is the last step.

plt({
    data => {
        Clinical => [
            [
                [@xw],    # x
                [@y]      # y
            ],
            [ [@xw], [ map { $_ + rand_between( -0.5, 0.5 ) } @y ] ],
            [ [@xw], [ map { $_ + rand_between( -0.5, 0.5 ) } @y ] ]
        ],
        HGI => [
            [
                [@xw],                            # x
                [ map { 1.9 - 1.1 / $_ } @xw ]    # y
            ],
            [ [@xw], [ map { $_ + rand_between( -0.5, 0.5 ) } @y ] ],
            [ [@xw], [ map { $_ + rand_between( -0.5, 0.5 ) } @y ] ]
        ]
    },
    'output.file' => 'output.images/single.wide.png',
    'plot.type'       => 'wide',
    color             => {
        Clinical => 'blue',
        HGI      => 'green'
    },
    title        => 'Visualization of similar lines plotted together',
    fh => $fh,
    execute      => 0,
});
# the last plot should have `execute => 1`
plt({
    data => [
        [
            [@xw],    # x
            [@y]      # y
        ],
        [ [@xw], [ map { $_ + rand_between( -0.5, 0.5 ) } @y ] ],
        [ [@xw], [ map { $_ + rand_between( -0.5, 0.5 ) } @y ] ]
    ],
    'output.file' => 'output.images/single.array.png',
    'plot.type'       => 'wide',
    color             => 'red',
    title             => 'Visualization of similar lines plotted together',
    fh                => $fh,
    execute           => 1,
});

Change log

0.28

colorbar options now work better in scatter.

Better warning when color key isn't defined for scatter

When giving two hash of hashes for a barplot, if one second key is defined in one subplot, but not the other, that subkey is initialized to 0.

Cross-platform support

The module now should run on Windows in addition to Linux and macOS.

The generated Python script is written to the system temporary directory (via File::Spec->tmpdir()) instead of a hard-coded /tmp, which does not exist on Windows.

The Python interpreter is now discovered automatically by probing, in order, python3, python, and the Windows py launcher, accepting the first that reports Python 3. This fixes Windows, where the interpreter is typically named python (not python3), and correctly rejects the Microsoft Store python3 stub and any Python 2. Set the MPLS_PYTHON (or PYTHON) environment variable to override the interpreter with a specific name or full path.

The Python script is now executed with the list form of system rather than a single shell string, so script paths containing spaces (common on Windows, e.g. C:\Users\First Last\AppData\Local\Temp) no longer break execution.

The Creator metadata embedded in the output file is now passed through write_data (base64), so Windows paths containing backslashes no longer produce invalid escape sequences (e.g. \U in C:\Users) in the generated Python string literal.

On Windows, Win32::Console::ANSI is loaded if available (it is optional, not a hard dependency) so colored status messages render on legacy consoles.

Crashes / generated-code fixes

violinplot is now a callable wrapper; it was exported and dispatched but never defined, so calling it died with "Undefined subroutine".

hist with an array of bins no longer emits a stray double-quote (e.g. [0,2,4"]) that caused a Python SyntaxError.

hexbin and hist2d no longer pass cblabel twice (once inside the option string and again as label => ...), which previously caused a duplicate-keyword SyntaxError.

scatter with a scalar set.options no longer emits a doubled comma (scatter(x, y, , ...)), which was a SyntaxError.

Stacked barh now uses the left keyword for stacking instead of bottom, which collided with barh's own bottom (y-position) parameter and raised "got multiple values for keyword argument 'bottom'".

colored_table with cb_logscale together with cb_min/cb_max no longer emits LogNorm(, vmin=...) with a leading comma (a SyntaxError).

plot with a hash of data and a scalar set.options no longer crashes by dereferencing a string as a hash under strict refs.

plot with a hash of data now accepts a scalar twinx naming a data key (e.g. twinx => 'pressure'); previously the value was wrongly required to be a digit string, making key-named twinx impossible.

Grouped bar plots with a single scalar color (e.g. color => 'green') no longer crash trying to dereference the string as an array; the color is applied to all series.

Incorrect-output fixes

colored_table no longer clobbers asymmetric data: filling undefined cells with np.nan previously also overwrote the mirror cell, destroying defined values (if A->B was defined but B->A was not, both became NaN).

colored_table now honors cb_min and cb_max; they were read from the wrong hash ($args instead of the plot options) and so were silently ignored.

colored_table now honors the cmap option; the color map and set_bad color were hard-coded to gist_rainbow regardless of the cmap given. The colormap is copied before calling set_bad, as registered colormaps are immutable in current matplotlib.

colored_table default row labels now mirror the column labels, matching the matrix that is actually built; with asymmetric data the old default could produce a row-label count mismatch ("'rowLabels' must be of length N").

scatter (single set, three keys) now honors the cmap option instead of always using gist_rainbow.

scatter now validates undefined values in both coordinate keys; the undefined-data check previously inspected only the first key.

Grouped, non-stacked bar widths are now divided by the number of bar series (plus one), not by a constant; the old divisor came from a hash that always held exactly one key, so groups with more than a few series overlapped their neighbors.

The wide plot no longer clamps the upper standard-deviation band at 1; that clamp assumed data in the range [0, 1] and clipped ordinary data (the documented example reaches roughly 1.9).

Numeric arguments to plt methods (e.g. margins => 0.2) are no longer quoted into strings; print_type now recognizes numbers.

plt.show() is now emitted after plt.savefig() (and only once), so using show no longer writes the file only after the interactive window is closed; output.file is no longer required when show is requested.

The add overlay's plot.type now correctly falls back to the parent plot's type when omitted, in both single- and multi-plot calls; the fallback was previously unreachable dead code, and an undefined type could be dispatched on.

Cleanups

Removed corrupted entries from the method whitelists ('set_mouseover( ' and a leading-space ' FixedFormatter') that made those options unusable.

Removed a stray default applied to the wrong hash in violin, two empty dead if blocks, and a duplicated die.

0.27

Better warnings for undefined data in scatter

color_key didn't work properly for multiple sets of data in scatter, which has now been fixed

0.26

ncol & nrow are synonymous with ncols and nrows respectively; testing now reflects these two specifically numeric options

no longer exports Data::Printer and Devel::Confess with the module, but is still used inside the module

'show.legend' option added to "hist", which is automatically turned off if there is only 1 group

"add" group is no longer deleted

"boxplot", "hist", and "violin" can take a single array, simplifying calls without requiring useless single keys when calling a single distribution

cb_min and cb_max now work for colored_table

"write_data" is no longer used in hist, as it prints numbers as strings (python3's types are a headache)

Instead, all values are checked in hist for being numeric before being sent to "write_data"

re-use undefined error array in hist_helper (slightly less RAM use)

0.25

re-used error array in scatter_helper

better warnings for undefined values in multiple-set scatterplots

fixed bug in scatterplot, where different sets would have the same label

"logscale" now available with "boxplot, "hist", "plot", "scatter"

$VERSION now prints with metadata for SVG output files, which required minor changes to testing

slightly better warnings in plot_helper

removed duplicate check from hist2d_helper

better warnings if wrong data types are given to "add"

Fixed bug in scatterplot, where color key could repeat on axes

colorbar can now be in logscale for colored_table

0.24

Newlines are now possible in key names for barplot and pie; other characters may be fixed too

@prop_cycle is only now taking RAM/valid where it's needed

new dependencies in JSON::MaybeXS and MIME::Base64 to prevent errors in key names

slight improvement in violinplot: "print" changed to "say" (1 less concatenation)

dynamic method wrappers are used, which save ~120 lines of code

re-used error array in "plt" to save RAM

better warning for non-File::Temp objects

more tests for wrapper subroutines

duplicate check removed from hexbin_helper

removed whiskers option from boxplot_helper, which didn't work the way that I thought that it did

removed shebang, which isn't necessary in .pm files

hist2d was missing an option for logscale on the axes, which it now has

0.23

colors for bar plots can be defined by hashes; e.g. colors => {A => 'red', B => 'green'}, etc

0.22

minor under-the-hood changes; "execute" subroutine, which was only called once, is now built into "plt" to save a function call; execution should be slightly faster/more efficient

0.21

"show" now works; files are still output if specified

0.20

better warnings for incomplete data in "plot" "plot" can plot with "twinx" when data is given in array or hash form "tick_params" is removed from plt methods fewer "my" for error arrays, using empty arrays from earlier; should increase efficiency slightly added tests for twinx in plot for both array and hash variants