in reply to SuperFormula with gnuplot and Tk

Hi, this is just a followup. Th Tkcanvas code for gnuplot uses quite a bit of extra cpu, all for the drawing the plot on a real Tk canvas. I use almost 40% cpu for the above script. You can get much improved performance by using the default gnuplot driver. See below. It uses less than 2% cpu, has no flicker due to contstant redrawing, and it can be dynamically resized. It is much superior, so I post it below. The tkcanvas method above would be useful only if you have a 1-shot plot, or if you want to save the canvas to postscript. So here is a better version.

#!/usr/bin/perl #use warnings; #use strict; use Tk; use Tk::ROText; use IPC::Open3; # see # for the formula # this script uses the X11 gnuplot driver for great efficiency $|++; my %var =( 'a1'=> 1, 'b1'=> 1, 'm1'=> 8, 'n1'=> 1, 'n2'=> 1, 'n3'=> 1, ); my $stop = 0; my $repeater; my $running = 0; my $mw = MainWindow->new; my $tframe = $mw->Frame()->pack(); #my $canvas = $tframe->Canvas( # -bg => 'white', # -height =>500, # -width =>500, # )->pack(-side=>'left',-expand=>1,-fill=>'both'); my $tframe1 = $tframe->Frame()->pack(-side=>'right',-padx=>0); my %scale; for ('a1','b1','m1','n1','n2','n3'){ my $tframea = $tframe1->Frame()->pack(-side=>'left',-padx=>0); $tframea->Label(-text => " $_ ")->pack(-side=>'top'); $scale{$_} = $tframea->Scale( -from => -100, -to => 100, -length => 500, -orient => 'vertical', -variable => \$var{$_}, -resolution => .01, -borderwidth =>0, -foreground => 'white', -background => 'lightslategrey', -troughcolor => 'powderblue', )->pack(-side => 'left', -padx=>0); } my $text = $mw->Scrolled('ROText', -bg=>'white', -height =>5, -width => 45) ->pack( -fill => 'both', -expand => 1 ); tie(*STDOUT, 'Tk::Text', $text); $text->tagConfigure( 'red', -foreground => 'red' ); my $pid = open3( \*gIN, \*gOUT, \*gERR, "/usr/bin/gnuplot" ) || die; $mw->fileevent( \*gOUT, readable => \&read_out ); $mw->fileevent( \*gERR, readable => \&read_err ); #comment out the below line to get gnuplot's X11 display #which is more efficient than the canvas plot #print gIN "set term tkcanvas perltk interactive\n"; print gIN "set term X11 noraise nopersist\n"; my $bframe = $mw->Frame->pack(); my $startbut = $bframe->Button( -text=>'Start', -command=> \&start)->pack(-side=>'left'); my $stopbut = $bframe->Button( -text=>'Stop', -command=> sub{ $auto = 0; $repeater->cancel; $running = 0; })->pack(-side=>'left'); #must be last or get broken pipe error tie(*STDERR, 'Tk::Text', $text); $mw->update; MainLoop; sub start{ my $string =<<"EOF"; reset unset border set clip set polar set xtics axis nomirror set ytics axis nomirror set zeroaxis set trange [0:2*pi] a=$var{'a1'} b=$var{'b1'} m=$var{'m1'} n1=$var{'n1'} n2=$var{'n2'} n3=$var{'n3'} butterfly(x) = ( ( abs(( (cos(m*x)/4))/a) )**n2 + ( abs(( (sin(m*x)/ +4))/b) )**n3 )**(-1/n1) set samples 800 set title "SuperFormula" unset key plot butterfly(t) EOF print gIN "$string\n"; if( $running == 0){ $repeater=$mw->repeat(500,sub{ $running = 1; my $string =<<"EOF"; a=$var{'a1'} b=$var{'b1'} m=$var{'m1'} n1=$var{'n1'} n2=$var{'n2'} n3=$var{'n3'} replot EOF print gIN "$string\n"; }); } } sub read_out { my $buffer = <gOUT>; $text->insert( 'end', $buffer); $text->see('end'); } sub read_err { my $num = sysread(gERR, my $buffer, 1024 ); $text->insert( 'end', $buffer, 'red' ); $text->see('end'); }

I'm not really a human, but I play one on earth. Cogito ergo sum a bum