perl - bioperl package Bio::Tree::Tree can't locate object method as_text -

i'm trying use as_text method bio::tree::tree message: can't locate object method as_text via package bio::tree::tree i'm using example here

note tried other methods in same package , worked normally.

my $input = new bio::treeio(-file   => "bintree.nw",                             -format => "newick"); $tree = $input->next_tree; $tree_as_string = $tree->as_text($format); print $tree_as_string; 

the print dumper($input) give result:

$var1 = bless( {                  '_bootstrap_style' => 'traditional',                  '_handler' => bless( {                                         '_treelevel' => 0,                                         '_currentnodes' => [],                                         '_lastitem' => {                                                          'tree' => 0,                                                          'current' => [],                                                          'id' => 0,                                                          'node' => 0,                                                          'leaf' => 0                                                        },                                         'nodetype' => 'bio::tree::node',                                         '_root_verbose' => 0,                                         'treetype' => 'bio::tree::tree',                                         '_currentitems' => [],                                         '_nodect' => [                                                        undef,                                                        2,                                                        0,                                                        0,                                                        0,                                                        0,                                                        0,                                                        0,                                                        0                                                      ]                                       }, 'bio::treeio::treeeventbuilder' ),                  '_file' => 'bintree.nw',                  'newline_each_node' => undef,                  'internal_node_id' => 'id',                  '_root_cleanup_methods' => [                                               sub { "dummy" }                                             ],                  '_flush_on_write' => 1,                  '_filehandle' => \*symbol::gen0,                  '_root_verbose' => 0,                  '_print_tree_count' => 0                }, 'bio::treeio::newick' ); 

here print dumper ($tree)

is there mistake ? or it's bug ? in advance

your code not working because have not set variable $format anything, bio::treeio class cannot find class load format. try code (it works me):

#!/usr/bin/env perl                                                                                                                                                            use strict; use warnings; use bio::treeio;  $usage  = "$0 treefile\n"; $infile = shift or die $usage; $treeio = bio::treeio->new(-file => $infile, -format => 'newick'); print $treeio->next_tree->as_text('newick'); 

edit: here version using tree input:

#!/usr/bin/env perl                                                                                                                                                            use strict; use warnings; use bio::treeio;  $treeio = bio::treeio->new(-fh => \*data, -format => 'newick'); print $treeio->next_tree->as_text('newick');  __data__ (((a:5,b:5)90:2,c:4)25:3,d:10); 

if run code, prints tree, expected.

$ perl so18645089.pl                                                                                     (((a:5,b:5)90:2,c:4)25:3,d:10); 

i'm using bioperl 1.6.901, latest version (and version documentation on cpan describes). version 1.6.0 old (>5 years) , not on cpan anymore. bet if upgrade, troubles disappear.