http://www.perlmonks.org?node_id=985597


in reply to Tk::Gauge errors

Take a closer look at your first subroutine. Make sure that you declare your variables. So, fixed:
sub button3_sub { my $mh = ( 35 + ( 29 - 1 ) * 6 ); my $cur = $mh; }
As for the rest, I couldn't reproduce your problem. This worked for me.
#!/usr/bin/perl use strict; use autodie; use warnings; use Tk; use Tk::Table; use Tk::Gauge; my $mw = MainWindow->new; $mw->geometry("75x75"); $mw->title("Gauge testing"); my $button = $mw->Button( -text => "Null", -command => \&button3_sub ) ->pack( -anchor => 'center' ); my ( $alpha, $alphaone, $beta, $betaone, $mh, $output_text, $gaugevar, + $cur ); sub button3_sub { my $mh = ( 35 + ( 29 - 1 ) * 6 ); my $cur = $mh; my $hw = $mw->Toplevel; $hw->geometry("650x450"); $hw->title('Health Track (!!!WARNING:DO NOT EXIT THIS WINDOW UNTIL + DONE)'); my $hf = $hw->Frame( -background => 'white' ) ->pack( -ipadx => 250, -fill => 'both', -expand => 'yes' ); my $left_frame = $hf->Frame( -background => 'white' ) ->pack( -side => 'left', -fill => 'y' ); my $right_frame = $hf->Frame( -background => 'white' ) ->pack( -ipadx => 150, -fill => 'y', -anchor => 'n', -expand => +1 ); $betaone = $left_frame->Entry( -background => "green", )->pack( -anchor => +'nw' ); my $beta_button = $left_frame->Button( -text => "Alpha Null", -command => \&update +_output ) ->pack( -anchor => 'nw' ); $alphaone = $left_frame->Entry( -background => "red", )->pack( -anchor => 'n +w' ); my $alpha_button = $left_frame->Button( -text => "Alpha Null", -command => \&update +_output ) ->pack( -anchor => 'nw' ); $output_text = $left_frame->Text( -height => 5, -width => 15 )->pack( -expand = +> 0, ); my $gauge = $right_frame->Gauge( -background => 'white', -bands => [ { -piecolor => 'green', -minimum => 50, -maximum => 100, -tag => 'Healthy', }, { -piecolor => 'yellow', -minimum => 25, -maximum => 50, -tag => 'Bloodied', }, { -piecolor => 'red', -minimum => 0, -maximum => 25, -tag => 'Critical', } ], -bandplace => 'underticks', -bandstyle => 'pieslice', -bandwidth => 0, -caption => 'Current Value', -captioncolor => 'black', -extent => -180, -from => 0, -hubcolor => 'black', -huboutline => 'blue', -hubradius => 15, -majortickinterval => 10, -majorticklabelplace => 'outside', -finetickinterval => 1, -minortickinterval => 5, -margin => 40, -needles => [ { -arrowshape => [ 12, 23, 6 ], -color => 'black', -command => undef, -format => '%d', -radius => 196, -showvalue => 1, -tag => 'null', -title => 'null', -titlecolor => 'white', -titlefont => 'Helvetica-12', -titleplace => 'south', -variable => \$gaugevar, -width => 5, } ], -start => 180, -to => 100, )->pack( -fill => 'both', -expand => 1 ); } sub gaugebutton1_sub { $gaugevar = ( $cur / $mh ) * 100; } sub update_output { my $beta = $betaone->get(); my $alpja = $alphaone->get(); if ( $alpha eq "" ) { $alpha = 0; } if ( $beta eq "" ) { $beta = 0; } $cur = $cur + $beta - $alpha; if ( $cur gt $mh ) { $cur = $mh; } if ( $cur lt 0 ) { $cur = 0; } my $output = "Current value:\n$cur"; $output_text->delete( '0.0', 'end' ); $output_text->insert( "end", $output ); $betaone->delete( '0.0', 'end' ); $alphaone->delete( '0.0', 'end' ); $gaugevar = ( $cur / $mh ) * 100; } MainLoop;