| Description: |
Real time data graphs. prompted me to try it. This is a realtime Tk data graph, getting the data through a socket connection. I made it as simple as I could for demo purposes. It will monitor for 86400 seconds ( broke the minutes into 10'ths). I also just let the sending script send a count (0..86400), mostly so I could speed it up for testing. In reality, you would want the sender to send the time of it's read, instead of the count. I noticed that as the data array(for the curve) got bigger, the cpu rate would rise to handle reconfiguring the curve with the huge array. So I broke the day into 500 second segments, which limits the point data array to 1000 elements. On my machine the cpu usage varied between 5 and 10% at high speed. Very low cpu with 1 second updates. There are 2 scripts, the socket-sender-test and the main Tk program. |
The socket-sender-test
#!/usr/bin/perl
use IO::Socket;
my $machine_addr = 'localhost';
$sock = new IO::Socket::INET(PeerAddr=>$machine_addr,
PeerPort=>7070,
Proto=>'tcp',
);
die "Could not connect: $!" unless $sock;
foreach my $count(1..86400){
my $temp = 800 + int(rand 100);
my $send = "$count $temp";
print $sock "$send\n";
print "$send\n";
select(undef,undef,undef,.1) ;
}
close ($sock);
__END__
And the Tk monitor
#!/usr/bin/perl
use warnings;
use strict;
use IO::Socket;
use Tk;
$|++;
my $listen = IO::Socket::INET->new(
Proto => 'tcp',
LocalPort => 7070,
Listen => 1,
Reuse => 1,
) or die "Can't create listen socket : $!\n";
my $margin = 50;
my $offset = 20; #axis offset
my $x_max = 86400;
my $y_max = 1000;
my $connected = 'Not Connected';
my %data; #why continuosly update the entire
#data set? cpu rate will climb, so
my $current_seg = 0; #break graph into 500 second segments
#to avoid cpu rate climbing, will create
# 86400/500 =~ 175 lines (data) segemnts
my $mw = tkinit;
$mw->fileevent($listen, 'readable', sub { new_connection($listen) });
my $scanvas = $mw->Scrolled('Canvas',
-width => 620,
-height => 420,
-scrollregion => [-$margin,-$margin,
$x_max + $margin,
$y_max + $margin + $offset ],
-bg => 'black')->pack();
&build_axis();
my $canvas = $scanvas->Subwidget('scrolled');
$canvas->Tk::bind("<Button-1>", [ \&print_xy, Ev('x'), Ev('y') ]);
sub print_xy {
my ($canv, $x, $y) = @_;
print "(x,y) = ", $canv->canvasx($x), ", ", $canv->canvasy($y), "\n"
+;
}
#for simplicity create the lines first
foreach my $line(0..172){
push @{$data{$line}{'data'}},0,0,0,0; #initilize, will remove later
$data{$line}{'line_obj'} = $canvas->createLine(
@{$data{$current_seg}{'data'}},
-width => 1,
-smooth => 1,
-fill => 'lightgreen');
}
my $subframe = $mw->Frame(-background =>'gray50')->pack(-fill => 'x');
$subframe->Button(-text =>'Exit',
-background => 'hotpink',
-activebackground => 'red',
-command => sub{ exit }
)->pack(-side=>'left',-padx=>40);
$subframe->Label(-textvariable => \$connected,
-background => 'black',
-foreground => 'green',
)->pack(-side=>'left');
MainLoop;
######################################################################
+#
sub new_connection {
my ($listen) = @_;
my $client = $listen->accept() or warn "Can't accept connection";
$client->autoflush(1);
$mw->fileevent($client, 'readable', sub { handle_connection($clien
+t) });
$connected = 'Connected';
}
sub handle_connection {
my ($client) = @_;
my $message = <$client>;
# print "$message\n";
# if( $message = eof){print "crashed\n"}
if ( defined $message ) {
$message =~ s/[\r\n]+$//;
my ($x, $y) = split( " ", $message);
if( $#{$data{$current_seg}{'data'}} > 1000 ){ #2 entries per poi
+nt
#initialize next segmnet, pop off last 2 of previous segment
my($xo,$yo) = @{$data{ $current_seg}{'data'}}[-2, -1 ];
$current_seg++;
print "current seg $current_seg\n";
#inititialize by overwriting the initial 0,0,0,0
${$data{$current_seg}{'data'}}[0] = $xo;
${$data{$current_seg}{'data'}}[1] = $yo;
${$data{$current_seg}{'data'}}[2] = $xo;
${$data{$current_seg}{'data'}}[3] = $yo;
}
push @{$data{$current_seg}{'data'}}, $x, $y;
$scanvas->coords( $data{$current_seg}{'line_obj'}, @{$data{$cu
+rrent_seg}{'data'}} );
#$scanvas->xviewScroll(1,'units');
$scanvas->xview('moveto', $x/86400 );
# $text->insert('end', "Got message [$message]\t");
# $text->see('end');
}
else {
#$text->insert('end', "Connection Closed\n");
#$text->see('end');
$client->close();
$connected = 'NOT Connected';
print "not connected\n";
}
}
##############################################################
sub build_axis{
# axis
my $xaxis = $scanvas->createLine( 0, $y_max + $offset, $x_max, $y_max
++ $offset,
-width => 1,
-fill => 'lightblue');
my $yaxis = $scanvas->createLine( 0, $y_max + $offset ,0,0,
-width => 1,
-fill => 'lightgreen');
# x axis ticks
my $tflag;
my $labflag;
my $min = 0;
my $minflag = 0;
my $hour = 0;
my $hourflag = 0;
my $tlength;
my $color;
for(1..$x_max){
$tflag = 0;
$tlength = 5;
$color = 'white';
$hourflag = 0;
$minflag = 0;
$labflag = 0;
if( ($_ % 10) == 0 ){ $tflag = 1 } #minutes are broken into 10 se
+c intervals
if( ($_ % 60) == 0 ){ $tlength = 15 ;
$color = 'yellow';
$min++;
$minflag = 1;
$labflag = 1;
}
if( ($_ % 3600) == 0 ){ $tlength = 25;
$color = 'hotpink';
$hour++;
$hourflag = 1;
$labflag = 1;
$min = 0;
$minflag = 0;
}
if( $tflag ){
$scanvas->createLine( $_, $y_max + $offset, $_, $y_max + $offset
+ + $tlength,
-width => 1,
-fill => $color);
if($labflag){
my $label;
if($minflag){ $label = $min; }
if($hourflag){ $label = $hour; }
$scanvas->createText( $_, $y_max + $offset + 1.2*$tlength,
-text => $label,
-fill => $color,
-anchor => 'n',
);
}
}
}
# y axis ticks
my $uflag;
my $midflag;
my @array = reverse(0..$y_max );
for(@array){
my $num = $y_max - $_; #reverse normal axis
$tflag = 0;
$tlength = 5;
$color = 'white';
$uflag = 0;
$midflag = 0;
$labflag = 0;
if( ($num % 10) == 0 ){ $tflag = 1 }
if( ($num % 50) == 0 ){ $tlength = 10 ;
$color = 'yellow';
$midflag = 1;
$labflag = 1;
}
if( ($num % 100) == 0 ){ $tlength = 20;
$color = 'hotpink';
$uflag = 1;
$labflag = 1;
$midflag = 0;
}
if( $tflag ){
$scanvas->createLine( 0 - $tlength, $num + $offset, 0, $num + $o
+ffset,
-width => 1,
-fill => $color);
if($labflag){
my $label;
if($midflag){ $label = $num; }
if($uflag){ $label = $num; }
$scanvas->createText( -20 , $y_max + $offset - $num ,
-text => $label,
-fill => $color,
-anchor => 'e',
);
}
}
}
$scanvas->xview('moveto',0);
$scanvas->yview('moveto',1);
}
|
Re: Tk Realtime data aquisition
by jaschwartz (Novice) on May 05, 2009 at 21:05 UTC
|
I am having some difficulty using your two scripts: If I start your sender script first I get an unspecified connect error "Could not connect: Unknown error at ....". If I start the monitor script first the sender script scrolls through some numbers, but nothing shows in the monitor graph as it also shows it not connected. Please help as I think I can greatly apply this script, but can't seem to get past these script/socket issues. Thanks :) | [reply] |
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You start the big Tk script first, and it will just sit there waiting for a connection. Start the smaller sender script second, and it should connect automatically.....works here I just tried it.
| [reply] |
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I started the big Tk script first, the monitor, and then started the smaller, the sender. The command line window I started it from shows incrementing numbers and its sent random number. But, nothing shows up in the monitor graph. I think some of the issue is that the monitor always shows "Not connected." I am not sure how to force it to connect? I am using a windows xp win32, is this the same as what you are using? After using a netstat -a, I see both the Listening on 7070 and the the established, but yet nothing shows up in the graph, I suspect this may be an issue in the the handle_connection subrutine. I uncommented your "print message line." But, nothing is printed. I suspect that handle_connection is not getting far enough to execute handle_connection. Your thoughts or advice?
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