plotpipe: Allow expressions.

plotpipe/plotpipe

@@ -9,7 +9,7 @@ plotpipe - Plot CSV data from a pipe
 
 =head1 SYNOPSIS
 
-I<datagenerator> | B<plotpipe> [-n] [-H] [-0] [--log axis] [-C str] [-h] [-V]
+I<datagenerator> | B<plotpipe> [-n] [-H] [-0] [--log axis] [-C str] [-h] [-V] [I<expression>]
 
 
 =head1 DESCRIPTION
@@ -24,6 +24,16 @@ titles on the plot.
 
 =over 4
 
+=item I<expression>
+
+Evaluate I<expression>. I<expression> consists of parts separated by
+,. Each part is evaluated as a Perl expression. You can use {I<n>} as
+the column value:
+
+  seq 10 | plotpipe '{1},{1},{1}**2,sqrt({1})'
+  (echo x y;paste <(seq 10) <(seq 11 20)) |
+    plotpipe {1},{2},{2}/{1}
+
 =item B<--colsep> I<string>
 
 =item B<-C> I<string>
@@ -76,7 +86,7 @@ Use \0 (NUL) instead of newline (\n) as record separator.
 
 =item B<-s> I<width>
 
-Smooth values. Take the average of I<width> y-values.
+Smooth values. Take the median of I<width> y-values.
 
 
 =item B<--version>
@@ -91,15 +101,15 @@ Show version
 
 =head1 EXAMPLE
 
-Plot the points (1,100) .. (100,1):
+Plot (1,100) .. (100,1):
 
   paste <(seq 100 -1 1) | plotpipe
 
-Plot the points (1,101) .. (100,200):
+Plot (1,101) .. (100,200):
 
   paste <(seq 100) <(seq 101 200) | plotpipe
 
-Plot the points (1,101) .. (100,200) and (1,300) .. (100,102):
+Plot (1,101) .. (100,200) and (1,300) .. (100,102):
 
   paste <(seq 100) <(seq 101 200) <(seq 300 -2 102) | plotpipe
 
@@ -146,11 +156,10 @@ input.csv:
 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),",",
+    plotpipe 'sin({1}*100)*0.3+0.5*cos({1}*2),
-              sin($_*2)-cos($_*100)*0.3,",",
+              sin({1}*2)-cos({1}*100)*0.3,
-              sin($_)+cos($_*99),",",
+              sin({1})+cos({1}*99),
-              sin($_*3)-cos($_*101)' |
+              sin({1}*3)-cos({1}*101)'
-    plotpipe
 
 
 =head1 LIMITS
@@ -189,7 +198,10 @@ B<pipeplot> uses B<gnuplot> and B<perl>.
 
 =head1 SEE ALSO
 
-B<gnuplot>, B<perl>
+B<gnuplot>, B<perl>, B<ploticus>
+(http://ploticus.sourceforge.net/doc/welcome.html), B<feedgnuplot>
+(https://github.com/dkogan/feedgnuplot), B<ttyplot>
+(https://github.com/tenox7/ttyplot)
 
 
 =cut
@@ -368,13 +380,15 @@ if(not GetOptions(options_hash())) {
 }
 
 $Global::progname = "plotpipe";
-$Global::version = 20210222;
+$Global::version = 20210302;
 if($opt::version) { version(); exit 0; }
 if($opt::help) { help(); exit 0; }
 if($opt::null) { $/ = "\0"; }
 
+my @eval_function = split/,/, join(" ",@ARGV);
+
 # Read csv
-my @csv = <>;
+my @csv = <STDIN>;
 
 # Title = lines starting with #
 my @title = map { s/^#//; s/"/''/g; $_ } map { "$_" } grep { /^#/ } @csv;
@@ -408,22 +422,41 @@ if($opt::header) {
 }
 
 # Convert input to perl table
-my $ncols = split /$opt::colsep/, $csv[0];
 my @tbl;
-if($ncols >= 2 and not $opt::nox) {
+for(@csv) {
-    # Column 1 = x-axis
-    for(@csv) {
     chomp;
     my @row = split /$opt::colsep/, $_;
     push @tbl,\@row;
+}
+
+# Eval
+if(@eval_function) {
+    for(@eval_function) {
+	my $new_header = $_;
+	$new_header =~ s/\{(\d+)\}/$header[$1-1] || "\\\\{$1\\\\}"/ge;
+	push @new_header, $new_header;
     }
+    $opt::header = 1;
+    @header = @new_header;
+    for my $row (@tbl) {
+	my @newrow = map {
+	    s/\{(\d+)\}/$row->[$1-1]/g;
+	    eval "$_"
+	} map { $_ } @eval_function;
+	$row = \@newrow;
+    }
+}
+
+# Add x-axis if needed
+my $ncols = $#{$tbl[0]}+1;
+if($ncols >= 2 and not $opt::nox) {
+    # Column 1 = x-axis  =>  Data is fine
 } else {
-    # All data = y-axis, invent x-axis
+    # All data = y-axis  =>  Invent x-axis
     my $x = 0;
-    for(@csv) {
+    for my $row (@tbl) {
-	chomp;
+	my @newrow = ($x++, @$row);
-	my @row = ($x++, split /$opt::colsep/, $_);
+	$row = \@newrow;
-	push @tbl,\@row;
     }
     # Prepend dummy header for x-axis
     unshift(@header,"");
@@ -438,6 +471,28 @@ if($opt::smooth) {
 	exit(255);
     }
     my $smooth = $opt::smooth-1;
+
+    sub median {
+	return ((sort { $a <=> $b } @_)[$#_/2]);
+    }
+    sub avg {
+	my $s=0;
+	map { $s += $_ } @_;
+	return ($s / ($#_+1));
+    }
+
+    for(my $x = 0; $x < $#tbl-$smooth; $x++) {
+	for (my $y = 0; $y <= $#{$tbl[$x]}; $y++) {
+	    my @med;
+	    for(my $m = $x; $m < $x+$smooth; $m++) {
+		push @med, $tbl[$m][$y];
+	    }
+	    $new[$x+$smooth/2][$y] = median(@med);
+	}
+    }
+    @tbl = @new;
+    
+    sub do_average() {
 	for(my $x = 0; $x < $smooth; $x++) {
 	    for (my $y = 0; $y <= $#{$tbl[$x]}; $y++) {
 		$sum[$y] += $tbl[$x][$y] / $opt::smooth;
@@ -451,6 +506,7 @@ if($opt::smooth) {
 	    }
 	}
 	@tbl = @new;
+    }
 }
 
 # Save data to tmpfile that will be read by Gnuplot