#! perl -w die unless ($size=$ARGV[0]); $center=($size-1)/2; $radsquared=$size*$size/4; print "P2\n$size $size\n1\n"; for $i(0..($size-1)) { $dx=$i-$center; for $j (0..($size-1)) { $dy=$j-$center; if ($dx*$dx+$dy*$dy<=$radsquared) { print "1" } else { print "0" } print " "; } print "\n"; }