NAME

Lab::Measurement - Log, describe and plot data on the fly

SYNOPSIS

use Lab::Measurement;

my $measurement=new Lab::Measurement(
    sample            => $sample,
    title             => $title,
    filename_base     => 'qpc_pinch_off',
    description       => $comment,

    live_plot         => 'QPC current',

    columns           => [
        {
            'unit'            => 'V',
            'label'           => 'Gate voltage',
            'description'     => 'Applied to gates via low path filter.',
        },
        {
            'unit'            => 'V',
            'label'           => 'Amplifier output',
            'description'     => "Voltage output by current amplifier set to $amp.",
        }
    ],
    axes              => [
        {
            'unit'            => 'V',
            'expression'      => '$C0',
            'label'           => 'Gate voltage',
            'min'             => ($start_voltage < $end_voltage) ? $start_voltage : $end_voltage,
            'max'             => ($start_voltage < $end_voltage) ? $end_voltage : $start_voltage,
            'description'     => 'Applied to gates via low path filter.',
        },
        {
            'unit'            => 'A',
            'expression'      => "abs(\$C1)*$amp",
            'label'           => 'QPC current',
            'description'     => 'Current through QPC',
        },
        {
            'unit'            => '2e^2/h',
            'expression'      => "(\$A1/$v_sd)/$g0)",
            'label'           => "Total conductance",
        },
        {
            'unit'            => '2e^2/h',
            'expression'      => "(1/(1/abs(\$C1)-1/$U_Kontakt)) * ($amp/($v_sd*$g0))",
            'label'           => "QPC conductance",
            'min'             => -0.1,
            'max'             => 5
        },

    ],
    plots             => {
        'QPC current'    => {
            'type'          => 'line',
            'xaxis'         => 0,
            'yaxis'         => 1,
            'grid'          => 'xtics ytics',
        },
        'QPC conductance'=> {
            'type'          => 'line',
            'xaxis'         => 0,
            'yaxis'         => 3,
            'grid'          => 'ytics',
        }
    },
);

$measurement->start_block();

my $stepsign=$step/abs($step);
for (my $volt=$start_voltage;$stepsign*$volt<=$stepsign*$end_voltage;$volt+=$step) {
    $knick->set_voltage($volt);
    usleep(500000);
    my $meas=$hp->read_voltage_dc(10,0.0001);
    $measurement->log_line($volt,$meas);
}

my $meta=$measurement->finish_measurement();

DESCRIPTION

If your measurements turn out to be shitty, it's not because of the software you are using.

CONSTRUCTORS

new

$measurement=new Lab::Measurement(%config);

where %config can contain

sample        => '',  # see Meta
title         => '',  # single line
filename      => '',
filename_base => '',  # for auto_naming
description   => '',  # multi line

columns       => [],
axes          => [],
plots         => [],  # See Meta

live_plot     => '',  # Name of plot that is to be plotted live
live_refresh  => '',
live_latest   => '',

writer_config => {},  # Configuration options for L<Lab::Data::Writer|Lab::Data::Writer>

METHODS

start_block

$block_num=$measurement->start_block($label);

log_line

$measurement->log_line(@data);

finish_measurement

$meta=$measurement->finish_measurement();

now_string

$now=$measurement->now_string();

log($datum,$column,$description)

magic log. deprecated.

SEE ALSO

Lab::Data::Meta

Lab::Data::Writer

Lab::Data::Plotter

AUTHOR/COPYRIGHT

This is $Id: Measurement.pm 452 2006-07-03 19:54:51Z schroeer $

Copyright 2004-2006 Daniel Schröer (http://www.danielschroeer.de)

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.