Re: Passing hash ref [ was Re: finding head and tail in data structure
Hi Jim,
On Fri, Jan 11, 2013 at 1:54 PM, Jim Gibson wrote:
> OR
>
> print_path( $id, $routes->{$id} );
> ...
> sub print_path
> {
> ...
> while( my ($start, $end) = each %$edges ) {
>
>
This is what i want, thank you!
Apparently passing "$routes->{$id}" is my earlier issue.
--budi
Re: Passing hash ref [ was Re: finding head and tail in data structure
On Jan 10, 2013, at 7:33 PM, budi pearl wrote:
> Hi All,
>
> I would like to pass hash: %{$routes{"ROUTE-252"}} instead of %routes but
> got this error:
>
> [budi@dev bin]$ ./print_path.pl
> Type of arg 1 to each must be hash (not hash element) at
> ./print_path.plline 38, near "}) "
> Execution of ./print_path.pl aborted due to compilation errors.
>
>
> #use strict;
If you had not commented out this line, Perl would have told you what the
problem is.
> use Graph::Directed;
> use Data::Dumper;
>
> my %routes = (
>"ROUTE-252" => {
># src => dest
> CX77 => "ABEP",
> ABEP => 441,
> 441 => 427,
> 427 => 444,
> 444 => "MGWQ",
> MGWQ => "CDEF"
>},
>
>"ROUTE-432" => {
> AAA => "BBB",
> BBB => "CCC",
> CCC => "DDD",
> DDD => "EEE",
> EEE => "FFF",
> XXX => "YYY",
> YYY => "ZZZ",
>}
> );
>
> my $id = "ROUTE-252";
> print Dumper $routes{$id};
>
> print_path($id, \%{$routes{$id}});
You are passing a reference to the inner hash, but you are doing it by first
de-referencing, then referencing the inner hash. This can be simply:
print_path( $id, $routes{$id} );
>
> sub print_path {
>my ($label, $edges) = @_;
You are storing the hash reference in the scalar variable $edges. This value is
$routes{'ROUTE-252'}.
>my $graph = Graph::Directed->new;
>
>while (my ($start, $end) = each $edges{$label}) {
There are two problems here:
1. $edges{$label} is a member of the hash %edges, but you have not declared or
defined %edges in your subroutine.
2. You are trying to access the member $route{'ROUTE-252'}->{'ROUTE-252'}. In
other words, you are indexing twice. You should either pass the top-level hash
and index in the subroutine, or pass the indexed hash member and do not index
in the subroutine:
print_path( $id, \%routes );
...
sub print_path
{
...
while( my ($start, $end) = each %{$edges->{$label}} ) {
OR
print_path( $id, $routes->{$id} );
...
sub print_path
{
...
while( my ($start, $end) = each %$edges ) {
> #while (my ($start, $end) = each %{$routes{$label}}) {
>$graph->add_edge($start, $end);
>}
>
>my @sinks = $graph->sink_vertices;
>for my $source ($graph->source_vertices) {
>for my $sink (grep $graph->is_sink_vertex($_),
> $graph->all_successors($source)) {
>print "$label: ", join ' - ', $graph->path_vertices($source,
> $sink);
>print "\n";
>}
>}
>
>
> }
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Re: Passing hash ref [ was Re: finding head and tail in data structure
On Fri, Jan 11, 2013 at 11:05 AM, budi pearl wrote:
> Hi Shawn,
>
> When trying to accessed inside subroutine , i got:
>
> Type of arg 1 to each must be hash (not hash element) at ./print_path.plline
> 41, near "}) "
>
> Execution of ./print_path.pl aborted due to compilation errors.
>
>
> this is work:
> while (my ($start, $end) = each %{$routes{$label}}) {
>
> but this not:
> while (my ($start, $end) = each %{$edges{$label}}) {
>
>
>
This will work, but this will pass %routes instead of %routes{$id}. Or it
should be that way?
my $hroute = \%routes;
print_path($id, $hroute);
...
while (my ($start, $end) = each %{$edges->{$label}}) {
Re: Passing hash ref [ was Re: finding head and tail in data structure
Hi Shawn,
When trying to accessed inside subroutine , i got:
Type of arg 1 to each must be hash (not hash element) at
./print_path.plline 41, near "}) "
Execution of ./print_path.pl aborted due to compilation errors.
this is work:
while (my ($start, $end) = each %{$routes{$label}}) {
but this not:
while (my ($start, $end) = each %{$edges{$label}}) {
Thanks.
--budhi
On Fri, Jan 11, 2013 at 10:47 AM, Shawn H Corey wrote:
> On Fri, 11 Jan 2013 10:33:02 +0700
> budi pearl wrote:
>
> > my $id = "ROUTE-252";
> > print Dumper $routes{$id};
> >
> > print_path($id, \%{$routes{$id}});
>
> I think you want:
>
> print_path( $id, $routes{$id} );
>
>
> --
> Don't stop where the ink does.
> Shawn
>
> --
> To unsubscribe, e-mail: beginners-unsubscr...@perl.org
> For additional commands, e-mail: beginners-h...@perl.org
> http://learn.perl.org/
>
>
>
Re: Passing hash ref [ was Re: finding head and tail in data structure
On Fri, 11 Jan 2013 10:33:02 +0700
budi pearl wrote:
> my $id = "ROUTE-252";
> print Dumper $routes{$id};
>
> print_path($id, \%{$routes{$id}});
I think you want:
print_path( $id, $routes{$id} );
--
Don't stop where the ink does.
Shawn
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Passing hash ref [ was Re: finding head and tail in data structure
Hi All,
I would like to pass hash: %{$routes{"ROUTE-252"}} instead of %routes but
got this error:
[budi@dev bin]$ ./print_path.pl
Type of arg 1 to each must be hash (not hash element) at
./print_path.plline 38, near "}) "
Execution of ./print_path.pl aborted due to compilation errors.
#use strict;
use Graph::Directed;
use Data::Dumper;
my %routes = (
"ROUTE-252" => {
# src => dest
CX77 => "ABEP",
ABEP => 441,
441 => 427,
427 => 444,
444 => "MGWQ",
MGWQ => "CDEF"
},
"ROUTE-432" => {
AAA => "BBB",
BBB => "CCC",
CCC => "DDD",
DDD => "EEE",
EEE => "FFF",
XXX => "YYY",
YYY => "ZZZ",
}
);
my $id = "ROUTE-252";
print Dumper $routes{$id};
print_path($id, \%{$routes{$id}});
sub print_path {
my ($label, $edges) = @_;
my $graph = Graph::Directed->new;
while (my ($start, $end) = each $edges{$label}) {
#while (my ($start, $end) = each %{$routes{$label}}) {
$graph->add_edge($start, $end);
}
my @sinks = $graph->sink_vertices;
for my $source ($graph->source_vertices) {
for my $sink (grep $graph->is_sink_vertex($_),
$graph->all_successors($source)) {
print "$label: ", join ' - ', $graph->path_vertices($source,
$sink);
print "\n";
}
}
}
