From 112ed474401ded8d572e07d89ab367adad1df6b2 Mon Sep 17 00:00:00 2001
From: Ole Tange <ole@tange.dk>
Date: Wed, 3 Mar 2021 22:18:06 +0100
Subject: [PATCH] plotpipe: --log axis.

---
 plotpipe/plotpipe | 83 ++++++++++++++++++++++++++++++++---------------
 1 file changed, 57 insertions(+), 26 deletions(-)

diff --git a/plotpipe/plotpipe b/plotpipe/plotpipe
index a3b78f5..5baeda0 100755
--- a/plotpipe/plotpipe
+++ b/plotpipe/plotpipe
@@ -9,12 +9,12 @@ plotpipe - Plot CSV data from a pipe
 
 =head1 SYNOPSIS
 
-I<datagenerator> | B<plotpipe> [-n] [-H] [-0] [--logx] [--logy] [-C str] [-h] [-V]
+I<datagenerator> | B<plotpipe> [-n] [-H] [-0] [--log axis] [-C str] [-h] [-V]
 
 
 =head1 DESCRIPTION
 
-B<plotpipe> is a simple wrapper for Gnuplot to simply plot data.
+B<plotpipe> is a simple wrapper for Gnuplot to simply plotting data.
 
 The input is a CSV-file. Lines starting with '#' will be used as
 titles on the plot.
@@ -48,11 +48,11 @@ B<--header>.
 Show help.
 
 
-=item B<--logx>
+=item B<--log x>
 
-=item B<--logy>
+=item B<--log y>
 
-=item B<--logxy>
+=item B<--log xy>
 
 Logarithmic X/Y/X&Y axis.
 
@@ -139,7 +139,18 @@ input.csv:
   4   9   16
   8   27  64
 
-  cat input.csv | plotpipe --nox --logy
+  cat input.csv | plotpipe --nox --log y
+
+=head1 EXAMPLE: XY-line plots
+
+You are not limited to a simple graph, but can also do XY-line plots.
+
+  seq 0 0.001 6.29 |
+    perl -nE 'say sin($_*100)*0.3+0.5*cos($_*2),",",
+              sin($_*2)-cos($_*100)*0.3,",",
+              sin($_)+cos($_*99),",",
+              sin($_*3)-cos($_*101)' |
+    plotpipe
 
 
 =head1 LIMITS
@@ -149,7 +160,7 @@ B<plotpipe> is limited by Gnuplot.
 
 =head1 AUTHOR
 
-Copyright (C) 2019-2020 Ole Tange,
+Copyright (C) 2019-2021 Ole Tange,
 http://ole.tange.dk and Free Software Foundation, Inc.
 
 
@@ -173,12 +184,12 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 =head1 DEPENDENCIES
 
-B<pipeplot> uses B<gnuplot>.
+B<pipeplot> uses B<gnuplot> and B<perl>.
 
 
 =head1 SEE ALSO
 
-B<perl>, B<gnuplot>
+B<gnuplot>, B<perl>
 
 
 =cut
@@ -193,9 +204,7 @@ sub options_hash() {
 	 "version|V" => \$opt::version,
 	 "colsep|col-sep|C=s" => \$opt::colsep,
 	 "help|h" => \$opt::help,
-	 "logx" => \$opt::logx,
-	 "logy" => \$opt::logy,
-	 "logxy" => \$opt::logxy,
+	 "log=s" => \$opt::log,
 	 "null|0" => \$opt::null,
 	 "nox|n" => \$opt::nox,
 	 "header|H" => \$opt::header,
@@ -208,7 +217,7 @@ sub version() {
     print join
 	("\n",
 	 "$Global::progname $Global::version",
-	 "Copyright (C) 2020 Ole Tange, http://ole.tange.dk and Free Software",
+	 "Copyright (C) 2020-2021 Ole Tange, http://ole.tange.dk and Free Software",
 	 "Foundation, Inc.",
 	 "License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>",
 	 "This is free software: you are free to change and redistribute it.",
@@ -219,6 +228,19 @@ sub version() {
         );
 }
 
+sub status(@) {
+    my @w = @_;
+    my $fh = $Global::status_fd || *STDERR;
+    print $fh map { ($_, "\n") } @w;
+    flush $fh;
+}
+
+sub error(@) {
+    my @w = @_;
+    my $prog = $Global::progname || "plotpipe";
+    status(map { ($prog.": Error: ". $_); } @w);
+}
+
 sub help() {
     # Returns: N/A
     print join
@@ -231,7 +253,7 @@ sub help() {
 	 '-0      Records separated by \0 instead of \n',
 	 '-C str  Columns separator',
 	 '-V      Show version',
-	 '--logx/logy/logxy Log x/y/x&y',
+	 '--log A Log axis A (x y xy)',
 	 '-n      No X value',
 	 '-s num  Smooth num Y-values',
 	 "",
@@ -341,9 +363,12 @@ sub find_sep(@) {
 
 
 Getopt::Long::Configure("bundling","require_order");
-my $retval = GetOptions(options_hash());
+if(not GetOptions(options_hash())) {
+    exit(255);
+}
+
 $Global::progname = "plotpipe";
-$Global::version = 20201222;
+$Global::version = 20210222;
 if($opt::version) { version(); exit 0; }
 if($opt::help) { help(); exit 0; }
 if($opt::null) { $/ = "\0"; }
@@ -409,8 +434,7 @@ if($ncols >= 2 and not $opt::nox) {
 if($opt::smooth) {
     my (@sum,@new);
     if($#tbl < $opt::smooth) {
-	print STDERR "plotpipe: --smooth must be lower than the ",
-	    "number of rows (",1+$#tbl,")\n";
+	error("--smooth must be lower than the number of rows (".(1+$#tbl).")");
 	exit(255);
     }
     my $smooth = $opt::smooth-1;
@@ -445,16 +469,23 @@ for(my $col = 2; $col <= $ncols; $col++) {
     if($opt::header) {
 	$legend = qq( title "$header[$col-1]");
     }
-    push @plotscript, qq("$filename" using 1:$col with lines $legend,);
+    push @legend, qq("$filename" using 1:$col with lines $legend,);
 }
 
-# Add --logx/--logy/--logxy to Gnuplot script
+# Add --log axis to Gnuplot script
 my @logscale;
-if($opt::logx or $opt::logxy) {
-    push @logscale, "set logscale x 10;";
-}
-if($opt::logy or $opt::logxy) {
-    push @logscale, "set logscale y 10;";
+if($opt::log) {
+    if($opt::log eq "x") {
+	push @logscale, "set logscale x 10;";
+    } elsif($opt::log eq "y") {
+	push @logscale, "set logscale y 10;";
+    } elsif($opt::log eq "xy" or $opt::log eq "yx") {
+	push @logscale, "set logscale x 10;";
+	push @logscale, "set logscale y 10;";
+    } else {
+	error("--log $opt::log is not supported. Only x y xy are supported");
+	exit(255);
+    }
 }
     
 # Make full Gnuplot script
@@ -467,7 +498,7 @@ set xlabel "$header[0]";
 set grid;
 set key right center;
 set datafile separator "\001";
-plot @plotscript
+plot @legend
 _EOS
 
 open GNUPLOT,"|-", "gnuplot -p -e ".Q($plotscript) or die;