I would appreciate your help with a translation to Python 3 that decomposes an input array of any size into smaller square arrays of length 4.
I have tried chunks and the array functions in numpy but they are useless for this.
Here is my code in Perl that works well, but I want it to compare to Python (in efficiency).
sub make_array {
my $input = shift;
my $result;
my @parts = split '-', $input;
$result = [];
# Test for valid number of lines in inputs
my $lines = scalar @parts;
if($lines % $width){
die "Invalid line count $lines not divisible by $width" ;
# Or could pad here by adding an entire row of '0'.
}
# Chunk input lines into NxN subarrays
# loop across all input lines in steps of N lines
my $line_width = 0;
for (my $nn=0;$nn<$lines;$nn+=$width){
# make a temp array to handle $width rows of input
my @temp = (0..$width-1);
for my $ii (0..$width-1){
my $p = $parts[$nn+$ii];
my $padding_needed = length($p) % $width;
if($padding_needed != 0) {
print "'$p' is not divisible by correct width of $width, Adding $padding_needed zeros\n";
for my $pp (0..$padding_needed){
$p .= "0";
}
}
if($line_width == 0){
$line_width = length($p);
}
$temp[$ii] = $p;
}
# now process temp array left to right, creating keys
my $chunks = ($line_width/$width);
if($DEBUG) { print "chunks: $chunks\n"; }
for (my $zz =0;$zz<$chunks;$zz++){
if($DEBUG) { print "zz:$zz\n"; }
my $key;
for (my $yy=0;$yy<$width;$yy++){
my $qq = $temp[$yy];
$key .= substr($qq,$zz*$width, $width) . "-";
}
chop $key; # lose the trailing '-'
if($DEBUG) { print "Key: $key\n"; }
push @$result, $key;
}
}
if($DEBUG){
print "Reformatted input:";
print Dumper $result;
my $count = scalar @$result;
print "There are $count keys to check against the lookup table\n";
}
return $result;
}
As an example, I have the following 12 x 12 matrix:
000011110011
000011110011
000011110011
000011110011
000011110011
000011110011
000011110011
000011110011
and I want it decomposed into 6 square submatrices of length 4:
0000 1111 0011
0000 1111 0011
0000 1111 0011
0000 1111 0011
0000 1111 0011
0000 1111 0011
0000 1111 0011
0000 1111 0011
The original matrix comes from a file (the program should read it from a text file) in the following format:
000011110011,000011110011,000011110011,000011110011,000011110011,000011110011,000011110011,000011110011
So the program needs to split it by hyphens and take each chunk as a row of the large matrix. The 6 submatrices should come in the same input format, hence the first one would be:
0000,0000,0000,0000
The program should decompose any input matrix into square matrices of length j, say 4, if the original matrix is of size not multiple of 4 then it should disregard the remaining chunks that couldn't form a 4x4 matrix.
Several large matrices of different size could come in the original input file, with break lines as separators. For example, the original large matrix together with anothe rmatrix would look like the following in a text file:
000011110011,000011110011,000011110011,000011110011,000011110011,000011110011,000011110011,000011110011\n
0101,0101,0101,0101
and retrieve the 2 sets of subarrays, one of 6 arrays of 4x4 and a single one of 4x4 for the second one. If you solve it for the single case is of course fine.
