commit 704c3f16074ce74add9e0c8681ccac9eb3b27f16
Author: Dima Kogan <dkogan@cds.caltech.edu>
Date:   Sat Dec 19 20:46:06 2009 -0800

    added realtime gnuplot script from
    http://users.softlab.ece.ntua.gr/~ttsiod/gnuplotStreaming.html

diff --git a/driveGnuPlots.pl b/driveGnuPlots.pl
new file mode 100755
index 0000000..82ed79f
--- /dev/null
+++ b/driveGnuPlots.pl
@@ -0,0 +1,104 @@
+#!/usr/bin/perl -w
+use strict;
+
+sub usage {
+    print "Usage: $0 <options>\n";
+    print <<OEF;
+where mandatory options are (in order):
+
+  NumberOfStreams                        How many streams to plot (windows)
+  Stream1_WindowSampleSize               this many samples per window
+  <Stream2_WindowSampleSize>             ...per stream2...
+...
+  <StreamN_WindowSampleSize>             ...per streamN...
+  Stream1_YRangeMin Stream1_YRangeMax    Min and Max values for stream 1
+  <Stream1_YRangeMin Stream1_YRangeMax>  Min and Max values for stream 2
+...
+  <StreamN_YRangeMin StreamN_YRangeMax>  Min and Max values for stream N
+
+OEF
+    exit(1);
+}
+
+sub Arg {
+    if ($#ARGV < $_[0]) {
+	print "Expected parameter missing...\n\n";
+	usage;
+    }
+    $ARGV[int($_[0])];
+}
+
+sub main {
+    my $argIdx = 0;
+    my $numberOfStreams = Arg($argIdx++);
+    print "Will display $numberOfStreams Streams (in $numberOfStreams windows)...\n";
+    my @sampleSizes;
+    for(my $i=0; $i<$numberOfStreams; $i++) {
+	my $samples = Arg($argIdx++);
+	push @sampleSizes, $samples;
+	print "Stream ".($i+1)." will use a window of $samples samples\n";
+    }
+    my @ranges;
+    for(my $i=0; $i<$numberOfStreams; $i++) {
+	my $miny = Arg($argIdx++);
+	my $maxy = Arg($argIdx++);
+	push @ranges, [ $miny, $maxy ];
+	print "Stream ".($i+1)." will use a range of [$miny, $maxy]\n";
+    }
+    my @gnuplots;
+    my @buffers;
+    shift @ARGV; # number of streams
+    for(my $i=0; $i<$numberOfStreams; $i++) {
+	shift @ARGV; # sample size
+	shift @ARGV; # miny
+	shift @ARGV; # maxy
+	local *PIPE;
+	open PIPE, "|gnuplot" || die "Can't initialize gnuplot number ".($i+1)."\n";
+	select((select(PIPE), $| = 1)[0]);
+	push @gnuplots, *PIPE;
+	print PIPE "set xtics\n";
+	print PIPE "set ytics\n";
+	print PIPE "set yrange [".($ranges[$i]->[0]).":".($ranges[$i]->[1])."]\n";
+	print PIPE "set style data linespoints\n";
+	print PIPE "set grid\n";
+	my @data = [];
+	push @buffers, @data;
+    }
+    my $streamIdx = 0;
+    select((select(STDOUT), $| = 1)[0]);
+    my $xcounter = 0;
+    while(<>) {
+	chomp;
+	my $buf = $buffers[$streamIdx];
+	my $pip = $gnuplots[$streamIdx];
+	
+	# data buffering (up to stream sample size)
+	push @{$buf}, $_;
+	#print "stream $streamIdx: ";
+	print $pip "set xrange [".($xcounter-$sampleSizes[$streamIdx]).":".($xcounter+1)."]\n";
+	print $pip "plot \"-\" notitle\n";
+	my $cnt = 0;
+	for my $elem (reverse @{$buf}) {
+	    #print " ".$elem;
+	    print $pip ($xcounter-$cnt)." ".$elem."\n";
+	    $cnt += 1;
+	}
+	#print "\n";
+	print $pip "e\n";
+	if ($cnt>=$sampleSizes[$streamIdx]) {
+	    shift @{$buf};
+	}
+	$streamIdx++;
+	if ($streamIdx == $numberOfStreams) {
+	    $streamIdx = 0;
+	    $xcounter++;
+	}
+    }
+    for(my $i=0; $i<$numberOfStreams; $i++) {
+	my $pip = $gnuplots[$i];
+	print $pip "exit;\n";
+	close $pip;
+    }
+}
+
+main;