Re^3: create a matrix for print 0 or 1 from pairing

Thanks

I have tried using that as per suggestions by Perlbotics /p>


#use strict;
use warnings;

my %A = (horse=> 'a',lion=>'b' ,mule=>'c',tiger =>'d');
my @order= sort  keys %A;

while (<DATA>) {
  warn("Line $.: cannot understand: $_") , next unless /(\w+);(\w+)/;
  my ($row, $col) = ($1,$2);
 $A {$row}{$col}++;
  $A{$col}{$row}++;
}

# print col. header
print "    ";
printf(" %2s",$_) for (@order);
print "\n";

#print matrix A
for my $row (@order) {
  printf(" %2s", $row);

  for my $col (@order) {
    printf(" %3d",  exists $A{$row}{$col} ? "1" : "0" );
  }
  print "\n";
}


__DATA__
horse;tiger
lion;mule
lion;tiger
horse;mule
[download]

I have got ouput 
        horse lion mule tiger
 horse   0   0   1   1
 lion   0   0   1   1
 mule   1   1   0   0
 tiger   1   1   0   0
[download]

However If u see in the code i have not use strict command; if using strict command in the first line error displayed will be Can't use string ("a") as a HASH ref while "strict refs" in use at work_matrix.pl line 12, <DATA> line 1.

What can be possible solution if using strict command?

Comment on Re^3: create a matrix for print 0 or 1 from pairing Select or Download Code

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Re^4: create a matrix for print 0 or 1 from pairing by jakobi (Pilgrim) on Oct 29, 2009 at 09:48 UTC
change lines 5+6 to `my %A; my @order=qw/horse lion mule tiger/;` Keywords to check are: soft references and auto-vivification: your strings 'a' to 'd' can be abused as soft references, which happens without `use strict`. With `use strict` however, you need a real hash-ref in the elements of `%A` instead - see perlreftut for more on references and soft references. Or omit the initialization of your hash-of-hashes `%A` to autovivify any `undef` values automagically as required (Autovivify definition or again: perlreftut). and for your aligning your table layout, consider something like sprintf "%5s", $stringvariable cu & HTH, Peter -- hints may be untested unless stated otherwise; use with caution & understanding.	[reply] [d/l] [select]

Replies are listed 'Best First'.

Re^4: create a matrix for print 0 or 1 from pairing
by jakobi (Pilgrim) on Oct 29, 2009 at 09:48 UTC

change lines 5+6 to my %A; my @order=qw/horse lion mule tiger/;

Keywords to check are: soft references and auto-vivification: your strings 'a' to 'd' can be abused as soft references, which happens without use strict. With use strict however, you need a real hash-ref in the elements of %A instead - see perlreftut for more on references and soft references. Or omit the initialization of your hash-of-hashes %A to autovivify any undef values automagically as required (Autovivify definition or again: perlreftut).

and for your aligning your table layout, consider something like sprintf "%5s", $stringvariable

cu & HTH, Peter -- hints may be untested unless stated otherwise; use with caution & understanding.

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