Linear regression

In the following script a SCAN, named RND, is created and filled with random numbers. The SCAN is copied to LR which is replaced by a linear regression of the data. The result is displayed, see below.

#!/usr/bin/perl -w 

use Spectra; 
use GQE; 
use strict; 

#
# delete everything
#
Spectra::delete();
#
# create the arrays
#
my @x_arr = ( 0 .. 100);
my @y_arr = ( 0 .. 100);
#
# fill the arrays
#
foreach my $x (@x_arr)
{
  $x = $x/10;
}
foreach my $y (@y_arr)
{
  $y = 10 + $y + Spectra::random()*10;
}
#
# create the SCAN
#
my $rnd = SCAN->create( name => "Rnd", 
			title => "Rnd", 
			x_ptr => \@x_arr,
			y_ptr => \@y_arr,
			colour => "red") or 
    die " Failed to create Rnd "; 
my $lr = SCAN->copy( from => $rnd,
		     to => "LR"); 
$lr->linearRegression();

Spectra::autoscale();
Spectra::display();
Spectra::gra_input();

Figure 10.1: A linear regresseion