--- name: "Math::VecStat" section: "3pm" platform: "linux" package: "libmath-vecstat-perl" version: "0.08-3" release: "Debian 13 (Trixie)" platforms: ["linux"] url: "https://new.carta.tech/Math::VecStat" --- # Math::VecStat(3pm) ## NAME ``` Math::VecStat - Some basic numeric stats on vectors ``` ## SYNOPSIS ``` use Math::VecStat qw(max min maxabs minabs sum average); $max=max(@vector); $max=max(\@vector); ($max,$imax)=max(@vector); ($max,$imax)=max(\@vector); $min=min(@vector); $min=min(\@vector); ($max,$imin)=min(@vector); ($max,$imin)=min(\@vector); $max=maxabs(@vector); $max=maxabs(\@vector); ($max,$imax)=maxabs(@vector); ($max,$imax)=maxabs(\@vector); $min=minabs(@vector); $min=minabs(\@vector); ($max,$imin)=minabs(@vector); ($max,$imin)=minabs(\@vector); $sum=sum($v1,$v2,...); $sum=sum(@vector); $sum=sum(\@vector); $average=average($v1,$v2,...); $av=average(@vector); $av=average(\@vector); $ref=vecprod($scalar,\@vector); $ok=ordered(@vector); $ok=ordered(\@vector); $ref=sumbyelement(\@vector1,\@vector2); $ref=diffbyelement(\@vector1,\@vector2); $ok=allequal(\@vector1,\@vector2); $ref=convolute(\@vector1,\@vector2); ``` ## DESCRIPTION This package provides some basic statistics on numerical vectors. All the subroutines can take a reference to the vector to be operated on. In some cases a copy of the vector is acceptable, but is not recommended for efficiency. - max(@vector), max(\\@vector) return the maximum value of given values or vector. In an array context returns the value and the index in the array where it occurs. - min(@vector), min(\\@vector) return the minimum value of given values or vector, In an array context returns the value and the index in the array where it occurs. - maxabs(@vector), maxabs(\\@vector) return the maximum value of absolute of the given values or vector. In an array context returns the value and the index in the array where it occurs. - minabs(@vector), minabs(\\@vector) return the minimum value of the absolute of the given values or vector. In an array context returns the value and the index in the array where it occurs. - sum($v1,$v2,...), sum(@vector), sum(\\@vector) return the sum of the given values or vector - average($v1,$v2,..), average(@vector), average(\\@vector) return the average of the given values or vector - vecprod($a,$v1,$v2,..), vecprod($a,@vector), vecprod( $a, \\@vector ) return a vector built by multiplying the scalar `$a` by each element of the `@vector`. - ordered($v1,$v2,..), ordered(@vector), ordered(\\@vector) return nonzero iff the vector is nondecreasing with respect to its index. To be used like ``` if( ordered( $lowBound, $value, $highBound ) ){ ``` instead of the (slightly) more clumsy ``` if( ($lowBound <= $value) && ($value <= $highBound) ) { ``` - sumbyelement( \\@array1, \\@array2 ), diffbyelement(\\@array1,\\@array2) return the element-by-element sum or difference of two identically-sized vectors. Given ``` $s = sumbyelement( [10,20,30], [1,2,3] ); $d = diffbyelement( [10,20,30], [1,2,3] ); ``` `$s` will be `"[11,22,33]"`, `$d` will be `"[9,18,27]"`. - allequal( \\@array1, \\@array2 ) returns true if and only if the two arrays are numerically identical. - convolute( \\@array1, \\@array2 ) return a reference to an array containing the element-by-element product of the two input arrays. I.e., ``` $r = convolute( [1,2,3], [-1,2,1] ); ``` returns a reference to ``` [-1,4,3] ``` - median evaluates the median, i.e. an element which separates the population in two halves. It returns a reference to a list whose first element is the median value and the second element is the index of the median element in the original vector. ``` $a = Math::VecStat::median( [9,8,7,6,5,4,3,2,1] ); ``` returns the list reference ``` [ 5, 4 ] ``` i.e. the median value is 5 and it is found at position 4 of the original array. If there are several elements of the array having the median value, e.g. \[1,3,3,3,5\]. In this case we choose always the first element in the original vector which is a median. In the example, we return \[3,1\]. =back =head1 HISTORY ``` $Log: VecStat.pm,v $ Revision 1.9 2003/04/20 00:49:00 spinellia@acm.org Perl 5.8 broke test 36, exposing inconsistency in C. Fixed, thanks to david@jamesgang.com. Revision 1.8 2001/01/26 11:10:00 spinellia@acm.org Added function median. Fixed test, thanks to Andreas Marcel Riechert Revision 1.7 2000/10/24 15:28:00 spinellia@acm.org Added functions allequal diffbyelement Created a reasonable test suite. Revision 1.6 2000/06/29 16:06:37 spinellia@acm.org Added functions vecprod, convolute, sumbyelement Revision 1.5 1997/02/26 17:20:37 willijar Added line before pod header so pod2man installs man page correctly Revision 1.4 1996/02/20 07:53:10 willijar Added ability to return index in array contex to max and min functions. Added minabs and maxabs functions. Thanks to Mark Borges for these suggestions. Revision 1.3 1996/01/06 11:03:30 willijar Fixed stupid bug that crept into looping in min and max functions Revision 1.2 1995/12/26 09:56:38 willijar Oops - removed xy data functions. Revision 1.1 1995/12/26 09:39:07 willijar Initial revision ``` ## BUGS Let me know. I welcome any appropriate additions for this package. ## AUTHORS John A.R. Williams \ Andrea Spinelli \