Re: Re: Re: getting my neighbours in an N-dimensional space

[Masem]

As one of your later posts implies you wanted points strictly closer to the origin, here's a quick function that helps to do that:

sub closer_to_origin {
   my ( $start, $test ) = @_;

   my $sd = 0; $sd += $_*$_ foreach (@$start);
   my $td = 0; $td += $_*$_ foreach (@$test);

   return ( $td < $sd );
}

Thus, in my original code block, where I have the grep, you can simply do:

my @closer_ns = grep { closer_to_origin( \@point, $_ ) } @n;

to get the closer neighbors. That routine basically calculates the distance from the point in question to the origin via the general distance formula, though without the final, expensive, square root as it's not necessary for magnitude comparison. This also blocks the original point from showing up (strictly closer, not same-or-closer distance) I'm sure that you can also modify tye's closure routine to include this check such that farther points don't pop up from each iteration loop.

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