G'day KuntalBhusan,

You haven't defined either $x or $y in $canvas->rotate($text,90,$x,$y);.

Looking at Tk::AbstractCanvas' Source, you'll see these values must be defined (the return() unless ... line): 

sub rotate { # takes as input id of obj to rot, angle to rot by, && op
+tional x,y point to rot about instead of obj center, if possible
  my($self, $obid, $angl, $xfoc, $yfoc)= @_; croak "rotate: Must suppl
+y an angle -" unless(defined($angl));
  my $type = $self->type($obid); # some objs need a pivot point to rot
+ate their center around
  return() unless(exists($_can_rotate_about_center{$type}) || (defined
+($xfoc) && defined($yfoc)));
  $_rotate_methods{$type}->($self, $obid, $angl, $xfoc, $yfoc);
}

[download]

-- Ken

In reply to Re: How to rotate text in Tk::Abstract Canvas ? by kcott
in thread How to rotate text in Tk::Abstract Canvas ? by KuntalBhusan

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.