my @normalized =
  map { $l2 + ($_ - $l1) * ($h2 - $l2) / ($h1 - $l1) }
  @data;
[download]

_____________________________________________________
Jeff[japhy]Pinyan: Perl, regex, and perl hacker, who'd like a job (NYC-area)
s++=END;++y(;-P)}y js++=;shajsj<++y(p-q)}?print:??;

Asking the question is answering it!

Use the following algorithm:

1. Call the minimum of your normalized range norm_min and the maximum of your normalized range norm_max.
2. Go through your list of figures and find the minimum (mini) and maximum (maxi) of the list.
3. Go again through the list, subtract mini from your number, multiply by (norm_max - norm_min) / (maxi - mini) and finally add norm_min.

$norm_min=1;
$norm_max=3;
$mini;
$maxi;
$mini=<DATA>;
$maxi=$mini;
@figures=<DATA>;
foreach (@figures) {
    chomp;
    $mini=$_ if $_<$mini;
    $maxi=$_ if $_>$maxi;
}
print "$mini  $maxi\n";

foreach (@figures) {
    chomp;
    my $result=($_ - $mini) * ($norm_max - $norm_min) / ($maxi - $mini
+) + $norm_min;
    print "$_: $result\n";

}


__DATA__
10
3
50
-8
100
67
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CountZero

"If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law

You want to produce a linear function mapping the minimum value in a list to 1 and the maximum in the list to 3. List::Util provides min() and max() functions. The coefficient of the linear term will be $m = (3 - 1)/(max(@list)-min(@list)), and the constant term will be $c = 1 - $m * min(@list). The map builtin will be handy to then apply that to the file data in @list.

After Compline,
Zaxo

can anyone provide a sample equation for a non-linear equation example? i.e. log, exponential, etc. ... (anything else you can think of). i would like to emphasize the numbers that are larger vs. the numbers that are smaller.

perl -e ' for( 0.03, 0.4, 5, 10 ) { print int(10**$_), "\n" } '

1
2
100000
10000000000
[download]

#!/usr/bin/perl -w

# tested A LITTLE

my ($file, $low, $hi) = @ARGV;

open ($file, "<$file") or die "open of '$file' failed: $!";

chomp(@vals = <$file>);

print "@vals\n";

@inrange = sort { $a <=> $b } (@vals);

$inmin = $inrange[0];
$inmax = $inrange[-1];

$delta = ( $hi - $low )/($inmax - $inmin);

@normal = map { $delta * ( $_ - $inmin)  + $low } @vals;

print "@normal\n";
[download]

You can do that by composing my answer with japhy's:

$l2 = 5;
$h2 = 15;
@data = ( 0.03, 0.1, 0.15, 0.5, 0.7 );

# exponential normalization

$l1 = 0.03;
$h1 = 0.7;
($l1,$h1) = map { 10**$_ } ($l1,$h1);
@normalized =
  map { $l2 + (10**$_ - $l1) * ($h2 - $l2) / ($h1 - $l1) }
  @data;

print " @normalized \n";
# 5 5.47560740136863 5.86545098040508 10.306017857952 15

# logarithmic normalization

$l1 = 0.03;
$h1 = 0.7;
($l1,$h1) = map { log($_) } ($l1,$h1);
@normalized =
  map { $l2 + (log($_) - $l1) * ($h2 - $l2) / ($h1 - $l1) }
  @data;

print " @normalized \n";
# 5 8.82227791363971 10.1095165638026 13.9317944774423 15
[download]