#!/usr/bin/perl -w
    use strict;
    use PDL;

    my $v1 = pdl reverse 1..10;
    my $v2 = pdl 0..9;
    my $v3 = pdl ((2)x10);

    my $add  = $v1 + $v2;
    my $mult = $v1 * $add;
    my $div  = $mult / $v3;
    my $sub  = $div - $v1;

    print "add:  $add\nmult: $mult\ndiv:  $div\nsub:  $sub\n";

    # we didn't stomp the original vectors either...
    # and of course, we can work with matrices too

    my $matA = pdl [0,0,0],[1,1,1],[2,2,2]; # 2d 3x3
    $matA++;         # add one across the board
    $matA *= 2;      # and scale up by factor of 2
    print "A: $matA\n";
    $matA *= $matA;  # scale it by itself
    print "B: $matA\n";
    $matA x= $matA;  # matrix multiply
    print "C: $matA\n";

    # and say, did you ever want to know the eigenvalues and
    # eigenvectors of a 4 x 4 matrix of a fibonacci sequence???

    use PDL::Slatec;           # Fortran never dies :-)
    my $fibo = fibonacci(4,4);
    my($eigvals, $eigvecs) = eigsys($fibo);
    print <<EOF;
    Fibo matrix: $fibo
    Eigenvalues: $eigvals
    Eigenvectors:$eigvecs
    EOF
    __END__


    add:  [10 10 10 10 10 10 10 10 10 10]
    mult: [100 90 80 70 60 50 40 30 20 10]
    div:  [50 45 40 35 30 25 20 15 10 5]
    sub:  [40 36 32 28 24 20 16 12 8 4]
    A: 
    [
     [2 2 2]
     [4 4 4]
     [6 6 6]
    ]

    B: 
    [
     [ 4  4  4]
     [16 16 16]
     [36 36 36]
    ]

    C: 
    [
     [ 224  224  224]
     [ 896  896  896]
     [2016 2016 2016]
    ]

    Fibo matrix: 
    [
     [  1   1   2   3]
     [  5   8  13  21]
     [ 34  55  89 144]
     [233 377 610 987]
    ]

    Eigenvalues: [0.859383 6.05138 68.0353 1010.05]
    Eigenvectors:
    [
     [    0.99101    -0.13375 -0.00326739  0.00031052]
     [  -0.131501    -0.97827    0.160279 -0.00218367]
     [ -0.0244236   -0.156787   -0.974861    0.156421]
     [  0.0032657   0.0227098    0.154745    0.987688]
    ]