Error message: Use of uninitialized value in concatenation (.) orstring

Hi All,

foreach my $ncbi_tax_id ( keys %{$new_proteins}) {
             my %kegg_map = ();
             my $up_tax_map = read_map ( 
"$up_maps_dir/$taxon_labels{$ncbi_tax_id}.map");
             foreach my $gene_id ( keys %{$new_proteins->{$ncbi_tax_id}}) {
                 foreach my $up_ac ( keys 
%{$new_proteins->{$ncbi_tax_id}{$gene_id}}) {
                     $kegg_map{$up_ac} = $up_tax_map->{$up_ac};
                 }
             }
             my $kegg_tax_map_path = 
"$kegg_maps_dir/$taxon_labels{$ncbi_tax_id}.kegg.map";
             open my $MAP, '>', $kegg_tax_map_path or croak "Failed to 
open for writing $kegg_tax_map_path: $!";
                 print $MAP "$up_ac\t$kegg_map{$up_ac}\n"; 
#-------------- line 441.
             }
             close $MAP;
         }

I get the following error message:
Use of uninitialized value in concatenation (.) or string at pipeline.pl 
line 441.

I would appreciate your input on this.

Thank you,

Aravind

• Error message: Use of uninitialized value in concatenation (.) orstring by venkates
• Re: Error message: Use of uninitialized value in concatenation (.) or string by Ken Slater