in reply to Re: How to restrict partitions (NestedLoops)
in thread How to restrict partitions

Instead of printing out the partitions, how could I plug them into (I guess) an array & then use them in a polynomial? What I've been using up to now (thx to hdb months ago) is

while (my ($x, $y, $z) = @{ $iter->next // [] }) { push @wants, map { { join(', ', $x, $y, $z) => $_ } } grep { is_approximately_an_integer( @$_ ) } [ poly_roots( poly_derivative( # expanded form of x*(x - $x)*(x - $y)*(x - $z) 1, -$x - $y - $z, $x*$y + $x*$z + $y*$z, -$x*$y*$z, 0 ) ) ]; }

The stuff in the while is from the Algorithm::Combinatorics module & the subroutine goes through the zeros of the polynomial's derivative to pick out the ones that have zeros that are all close enough to an integer. I guess it would be to get the elements of @cnt in the prog above but I'm not sure how to do that. Is it as simple as replacing the $x, $y, $z with $cnt[0], $cnt1, $cnt2 in the code above? Or maybe defining my $x = $cnt[0]?

(a couple minutes later)

my @cnt; my $seq= 0; my $x = $cnt[0]; my $y = $cnt[1]; my $z = $cnt[2]; while( @cnt = $iter->() ) { #printf "%d) %s\n", ++$seq, join ' + ', @cnt map { { join(', ', $x, $y, $z) => $_ } } grep { is_approximately_an_integer( @$_ ) } [ poly_roots( poly_derivative( # expanded form of x*(x - $x)*(x - $y)*(x - $z) 1, -$x - $y - $z, $x*$y + $x*$z + $y*$z, -$x*$y*$z, 0 ) ) ]; }

Actually, now that I've tried that, I get errors in the line with the map & also the following one with the grep saying $x, $y, $z are uninitialized which I don't understand because I set them to be elements of @cnt.

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Re^3: How to restrict partitions (NestedLoops)
by tye (Sage) on Jan 27, 2014 at 07:06 UTC
    while( my( $x, $y, $z ) = $iter->() ) {

    - tye        

      I got it working. Thx again! You & hdb are lifesavers :)