NAME

rash - raster shell - a Perl shell for raster algebra

SYNOPSIS

rash.pl <options>

DESCRIPTION

rash is an extension of the basic Perl shell:

    while (<>) {
	eval;
	print $@;
    }

BASIC FUNCTIONALITY

rash uses Geo::Raster, thus rasters and PGPLOT graphics can be used readily. rash adds command line editing and history with Term::ReadLine. Database connectivity is added using the functionality provided by Raster module. rash can open a pipe to gnuplot for plotting data.

OPTIONS AND ARGUMENTS

-a

Same as specifying both --db-connection and --gnuplot. Tries to open a database connection into Raster module and a pipe to gnuplot.

--db-connection

Tries to open a database connection into Raster module. The default hostname ('' by Raster.pm) can be overridden with option -h hostname or argument --hostname=hostname. The default database (the name of the current directory by Raster.pm) can be overridden with argument --database=database. The default username with which to connect (the effective userid by Raster.pm) can be overridden with argument --username=username.

--gnuplot

Tries to open (an unbuffered) pipe GNUPLOT to gnuplot.

Options can be set from the rash command line with command options(..list of options and arguments...)

COMMANDS

output

Command output(filename) directs all output to file filename. If filename is not given, directs all output to STDOUT.

p

Command p is the standard perl print except when the first parameter is a reference to a hash or to an array. If the first parameter is a hash reference, p sorts the hash numerically and prints it using two columns (separated by single space) or several columns if the values are references to arrays. If the first parameter is a hash reference, p prints the array elements, each on its own row. If the element is a reference to an array, it is expanded.

plot

Command plot(argument,options) plots the argument using gnuplot. The argument should be either a reference to a hash (the returned value of raster method contents, histogram, or some such) or a string. The options should be a hash, i.e, a list of key, value -pairs written using the format: key1=>value1, key1=>value1, ...

For example:

plot($raster->contents,title=>'cell count of raster',with=>'impulses');

A hash argument is printed to a temporary file (.raster-tmp) and the command line

plot xrange ".raster-tmp" title with with

range = '' or [keymin-1:keymax+1] if with equals 'impulses'

title = 'notitle' or 'title title' if title is given in the command line as an option title=>'title'

with = 'lines' or what is given as an option with=>'with'

is piped to gnuplot.

A string argument is piped to gnuplot as a part of the command line

plot xrange yrange argument title

xrange, yrange, and title are empty strings or those given as options. If argument is a readable file, it is surrounded by double quotation marks.

Gnuplot can be instructed to plot into a png-file using option file=>1.

slurp

Command slurp(filename,options) reads the contents of a file into a hash (or an array, if option array=>1 is given). It is assumed that the file contains data in two (for hash) or more columns (for a array). In the case of an array the array values are references to arrays which each hold the values of one row of data.

vars

Command vars lists all variables, and if they are references, the type of data which they refer to.

SIGINT

rash installs a SIGINT handler which may used to cancel lengthy raster operations.

HELP

Commands ? and help run perldoc rash thus showing this manual page.

Command ? Raster and help Raster run man Raster thus showing the manual page of the Raster module.

EXECUTING SYSTEM COMMANDS

A command line which begins with '!' is interpreted as a system command.

cpanm Geo::Raster

perl -MCPAN -e shell
install Geo::Raster