-#!/usr/local/bin/perl
-##############################################################################
-# Time-stamp: <Sat Oct 28 1995 23:15:13 Stardate: [-31]6509.63 hwloidl>
-#
-# Usage: do ....
-#
-# Statistics package that is used in gran-extr, RTS2gran and friends.
-# Most of the routines assume a list of integers as input.
-# This package contains:
-# - corr
-# - mean_std_dev
-# - cov
-# - list_sum
-# - list_max
-# - list_min
-#
-##############################################################################
-
-# ----------------------------------------------------------------------------
-# Compute correlation of 2 vectors, having their sums precomputed.
-# Usage: do corr(($n, $sum_1, @rest);
-#
-# Input: $n ... number of all elements in @list_1 as well as in @list_2
-# (i.e. $n = $#list_1+1 = $#list_2+1).
-# $sum_1 ... sum of all elements in @list_1
-# @list_1 ... list of integers; first vector
-# $sum_2 ... sum of all elements in @list_2
-# @list_2 ... list of integers; first vector
-# Output: correlation of @list_1 and @list_2
-# ----------------------------------------------------------------------------
-
-sub corr {
- local ($n, $sum_1, @rest) = @_;
- local (@list_1) = splice(@rest,0,$n);
- local ($sum_2, @list_2) = @rest;
-
- local ($mean_1,$mean_2,$std_dev_1,$std_dev_2);
-
- if ( $opt_D ) {
- print "\ncorr: n=$n sum_1=$sum_1 sum_2=$sum_2\n";
- print " list_sum of list_1=" . &list_sum(@list_1) .
- " list_sum of list_2=" . &list_sum(@list_2) . "\n";
- print " len of list_1=$#list_1 len of list_2=$#list_2\n";
- }
-
- ($mean_1, $std_dev_1) = &mean_std_dev($sum_1,@list_1);
- ($mean_2, $std_dev_2) = &mean_std_dev($sum_2,@list_2);
-
- if ( $opt_D ) {
- print "corr: $mean_1, $std_dev_1; $mean_2, $std_dev_2\n";
- }
-
- return ( ($std_dev_1 * $std_dev_2) == 0 ?
- 0 :
- &cov($n, $mean_1, @list_1, $mean_2, @list_2) /
- ( $std_dev_1 * $std_dev_2 ) );
-}
-
-# ----------------------------------------------------------------------------
-
-sub mean_std_dev {
- local ($sum,@list) = @_;
- local ($n, $s, $s_);
-
- #print "\nmean_std_dev: sum is $sum ; list has length $#list";
-
- $n = $#list+1;
- $mean_value = $sum/$n;
-
- $s_ = 0;
- foreach $x (@list) {
- $s_ += $x;
- $s += ($mean_value - $x) ** 2;
- }
- if ( $sum != $s_ ) {
- print "stat.pl: ERROR in mean_std_dev: provided sum is wrong " .
- "(provided: $sum; computed: $s_ " .
- ";list_sum: " . &list_sum(@list) . "\n";
- exit (2);
- }
-
- return ( ($mean_value, sqrt($s / ($n - 1)) ) );
-}
-
-# ----------------------------------------------------------------------------
-
-sub _mean_std_dev {
- return ( &mean_std_dev(&list_sum(@_), @_) );
-}
-
-# ----------------------------------------------------------------------------
-# Compute covariance of 2 vectors, having their sums precomputed.
-# Input: $n ... number of all elements in @list_1 as well as in @list_2
-# (i.e. $n = $#list_1+1 = $#list_2+1).
-# $mean_1 ... mean value of all elements in @list_1
-# @list_1 ... list of integers; first vector
-# $mean_2 ... mean value of all elements in @list_2
-# @list_2 ... list of integers; first vector
-# Output: covariance of @list_1 and @list_2
-# ----------------------------------------------------------------------------
-
-sub cov {
- local ($n, $mean_1, @rest) = @_;
- local (@list_1) = splice(@rest,0,$n);
- local ($mean_2, @list_2) = @rest;
-
- local ($i,$s,$s_1,$s_2);
-
- for ($i=0; $i<$n; $i++) {
- $s_1 += $list_1[$i];
- $s_2 += $list_2[$i];
- $s += ($mean_1 - $list_1[$i]) * ($mean_2 - $list_2[$i]);
- }
- if ( $mean_1 != ($s_1/$n) ) {
- print "stat.pl: ERROR in cov: provided mean value is wrong " .
- "(provided: $mean_1; computed: " . ($s_1/$n) . ")\n";
- exit (2);
- }
- if ( $mean_2 != ($s_2/$n) ) {
- print "stat.pl: ERROR in cov: provided mean value is wrong " .
- "(provided: $mean_2; computed: " . ($s_2/$n) . ")\n";
- exit (2);
- }
- return ( $s / ($n - 1) ) ;
-}
-
-# ---------------------------------------------------------------------------
-
-sub list_sum {
- local (@list) = @_;
- local ($sum) = (0);
-
- foreach $x (@list) {
- $sum += $x;
- }
-
- return ($sum);
-}
-
-# ----------------------------------------------------------------------------
-
-sub list_max {
- local (@list) = @_;
- local ($max) = shift;
-
- foreach $x (@list) {
- $max = $x if $x > $max;
- }
-
- return ($max);
-}
-
-# ----------------------------------------------------------------------------
-
-sub list_min {
- local (@list) = @_;
- local ($min) = shift;
-
- foreach $x (@list) {
- $min = $x if $x < $min;
- }
-
- return ($min);
-}
-
-# ----------------------------------------------------------------------------
-
-1;