The previous post by poj prints:

0
0.0175    0
0.0483    0.0471    0
0.0507    0.0483    0.0287    0
[download]

I don't see anywhere in your spec where these extra zeroes are required or even desired!
Please be very specific about the requirements.

I recommend something like this:

#!/usr/bin/perl
use strict;
use warnings;

my @array = qw(
-- 0.0175 0.0483 0.0507
-- 0.0471 0.0483
-- 0.0287
--);

my @twod_array;

my $i_col = -1;
my $i_row;

foreach my $ele (@array)
{
   if ($ele eq '--')
   {
      $i_col++;         #new column starts
      $i_row = $i_col;
      next;
   }
   
   $twod_array[$i_row++][$i_col] = $ele;
}

foreach my $row_ref (@twod_array)
{
   print join ("\t",@$row_ref),"\n";
}


__END__
0.0175
0.0483    0.0471
0.0507    0.0483    0.0287
[download]