fix ASCII plots to work in multiplot with Gnuplot 6+

CHANGES

@@ -1,5 +1,6 @@
 - add "resample" curve option for with=>'fits'
 - with=>'fits' error if no FITS header
+- fix ASCII plots to work in multiplot with Gnuplot 6+
 
 2.026 2024-04-20
 - fix {colorbox=>1} (#100)

lib/PDL/Graphics/Gnuplot.pm

@@ -3128,7 +3128,7 @@ POS
 		$chunks->[$i]{testdata} = $testdataunit_binary x ($chunks->[$i]{tuplesize}) if $check_syntax;
 	    } else {
 		# ASCII transfer has been specified - plot command is easier, but the data are in ASCII.
-		$pchunk = " '-' ".$plotcmds[$i];
+		$pchunk = " \$PGG_data_$i ".$plotcmds[$i];
 		$tchunk = $pchunk if $check_syntax;
 		$chunks->[$i]{testdata} = " 1 " x ($chunks->[$i]{tuplesize}) . "\ne\n" if $check_syntax;
 	    }
@@ -3160,12 +3160,13 @@ POS
     ##############################
     ##### Send the PlotOptionsString
     my @plot_chunks = [$plotOptionsString];
-    my $plotshow = $plotOptionsString;
+    my @plotshow_chunks = $plotOptionsString;
     ##############################
     ##### Finally..... send the actual plot command to the gnuplot device.
     print "plot command is:\n$plotcmd\n" if $PDL::Graphics::Gnuplot::DEBUG;
     push @plot_chunks, [$plotcmd];
-    $plotshow .= $plotcmd;
+    push @plotshow_chunks, $plotcmd;
+    my $chunk_i = 0;
     for my $chunk (@$chunks) {
 	# Gnuplot doesn't handle bad values, but it *does* know to
 	# omit nans.  If we're running under a PDL that uses the
@@ -3184,22 +3185,22 @@ POS
 	    # Currently all images are sent binary
 	    my $p = $chunk->{data}[0]->double->sever;
 	    push @plot_chunks, [${$p->get_dataref}, {binary => 1, data => 1 }];
-	    $plotshow .= " [ ".length(${$p->get_dataref})." bytes of binary image data ]\n";
+	    push @plotshow_chunks, " [ ".length(${$p->get_dataref})." bytes of binary image data ]\n";
 	} elsif ($chunk->{binaryCurveFlag}) {
 	    # Send in binary if the binary flag is set.
 	    my $p = pdl(@{$chunk->{data}})->mv(-1,0)->double->sever;
 	    push @plot_chunks, [${$p->get_dataref}, {binary => 1, data => 1 }];
-	    $plotshow .= " [ ".length(${$p->get_dataref})." bytes of binary data ]\n";
+	    push @plotshow_chunks, " [ ".length(${$p->get_dataref})." bytes of binary data ]\n";
 	} else {
 	    # Assemble and dump the ASCII
 	    if ($chunk->{data}[0]->$_isa('PDL')) {
 		# It's a collection of PDL data only.
 		my $p = pdl(@{$chunk->{data}})->slice(":,:"); # ensure at least 2 dims
 		$p = $p->mv(-1,0);                         # tuple dim first, rows second
-		$plotshow .= " [ ".$p->dim(1)." lines of ASCII data ]\n";
+		splice @plotshow_chunks, 1, 0, "\$PGG_data_$chunk_i << [ ".$p->dim(1)." lines of ASCII data ]\n";
 		# Create a set of ASCII lines.  If any of the elements of a given row are NaN or BAD, blank that line.
 		my $outbuf = join("\n", map $_->isfinite->all ? join(" ", $_->list) : "", $p->dog) . "\n";
-		push @plot_chunks, _emit_ascii($this, $outbuf);
+		splice @plot_chunks, 1, 0, _emit_ascii($this, $chunk_i, $outbuf);
 	    } else {
 		# It's a collection of array ref data only.  Assemble strings.
 		my $data = $chunk->{data};
@@ -3217,10 +3218,11 @@ POS
 		    }
 		    $s .= "\n";                     # add newline
 		}
-		$plotshow .= $s;
-		push @plot_chunks, _emit_ascii($this, $s);
+		splice @plotshow_chunks, 1, 0, "\$PGG_data_$chunk_i << e\n${s}e\n";
+		splice @plot_chunks, 1, 0, _emit_ascii($this, $chunk_i, $s);
 	    }
 	}
+	$chunk_i++;
     }
     ##############################
     # Finally, finally ...  send any required cleanup commands.  This
@@ -3239,10 +3241,10 @@ POS
 	  if $checkpointMessage;
     }
     push @plot_chunks, [$cleanup_cmd];
-    $plotshow .= $cleanup_cmd;
+    push @plotshow_chunks, $cleanup_cmd;
     # Flag the output as rescalable if anti-aliasing is in effect
     $this->{aa_ready} = 1 if $this->{aa} && $this->{aa} != 1;
-    (\@plot_chunks, $plotshow);
+    (\@plot_chunks, join('', @plotshow_chunks));
 }
 
 *gplot = \&plot;
@@ -3306,12 +3308,12 @@ sub plot
 # Not in binary mode - send this chunk in ASCII.  Each line gets one
 # tuple, followed a line with just "e".
 sub _emit_ascii {
-  my ($this, $chunk) = @_;
+  my ($this, $chunk_i, $chunk) = @_;
   # Under real OSes, we can just send a schwack of stuff - there is no echo.
-  return [$chunk."e\n", {data => 1}]
+  return ["\$PGG_data_$chunk_i << e\n${chunk}e\n", {data => 1}]
     if !$MS_io_braindamage;
   my $pipe_stuff = !$this->{dumping} && $echo_eating;
-  ((map $pipe_stuff ? \$_ : $_, map ["$_\n", {data => 1 }], split /\n/, $chunk), ["e\n", {data => 1 }]);
+  ((map $pipe_stuff ? \$_ : $_, map ["$_\n", {data => 1 }], "\$PGG_data_$chunk_i <<e", split /\n/, $chunk), ["e\n", {data => 1 }]);
 }
 
 #####################

t/plot.t

@@ -208,7 +208,7 @@ is($@, '', "ascii array-ref plot succeeded");
 
 my $text = eval { $w->plot_generate( xvals(5), xvals(5)**2 ); };
 is($@, '', "plot_generate succeeded");
-like $text, qr/plot\s*'-'\s*using 1:2 notitle with lines\s*dt solid/, 'plot_generate';
+like $text, qr/plot\s*\$PGG_data_\d+\s*using 1:2 notitle with lines\s*dt solid/, 'plot_generate';
 
 eval { $w->plot( xvals(10000), xvals(10000)->sqrt ); };
 is($@, '', "looong ascii plot succeeded ");
@@ -836,6 +836,20 @@ undef $@;
 eval { $w->options(justify=>"1") };
 is($@, '', "justify accepts positive numbers");
 
+eval {
+  $w = gpwin('dumb', output=>$testoutput);
+  $w->multiplot(layout=>[1,1]);
+  $w->plot(
+    {
+      label => [ [ 'left-justified', at=>[0,0], 'left' ] ],
+      xrange => [ 0, 4 ], yrange => [ -1, 5 ]
+    },
+    { with => 'labels' },
+    [ 0 ], [ -1 ], [ '' ]
+  );
+};
+is($@, '', "labels with multiplot works even in Gnuplot 6.0.1");
+
 ##############################
 ##############################
 ## Test explicit and implicit plotting in 2-D and 3-D, both binary and ASCII
@@ -848,31 +862,31 @@ $w->options(binary=>0);
 eval { $w->plot(with=>'lines',xvals(5)) };
 is($@, '', "ascii plot with implicit col succeeded");
 
-like($PDL::Graphics::Gnuplot::last_plotcmd, qr/plot +'-' +using 0\:1 /,
+like($PDL::Graphics::Gnuplot::last_plotcmd, qr/plot +\$PGG_data_\d+ +using 0\:1 /,
    "ascii plot with implicit col uses explicit reference to column 0");
 
 eval { $w->plot(with=>'lines',xvals(5),xvals(5)) };
 is($@, '', "ascii plot with no implicit col succeeded");
-like($PDL::Graphics::Gnuplot::last_plotcmd, qr/plot +'-' +using 1\:2 /s,
+like($PDL::Graphics::Gnuplot::last_plotcmd, qr/plot +\$PGG_data_\d+ +using 1\:2 /s,
    "ascii plot with no implicit cols uses columns 1 and 2");
 
 eval { $w->plot(with=>'lines',xvals(5,5)) };
 is($@, '', "ascii plot with threaded data and implicit column succeeded");
-like($PDL::Graphics::Gnuplot::last_plotcmd, qr/plot +'-' +using 0\:1 [^u]+using 0\:1 /s,
+like($PDL::Graphics::Gnuplot::last_plotcmd, qr/plot +\$PGG_data_\d+ +using 0\:1 [^u]+using 0\:1 /s,
    "threaded ascii plot with one implicit col does the Right Thing");
 
 
 eval { $w->plot(with=>'lines',xvals(5),{trid=>1}) };
 is($@, '', "ascii 3-d plot with 2 implicit cols succeeded");
-like($PDL::Graphics::Gnuplot::last_plotcmd, qr/plot +'-' +using 0:\(\$0\*0\):1/s,
+like($PDL::Graphics::Gnuplot::last_plotcmd, qr/plot +\$PGG_data_\d+ +using 0:\(\$0\*0\):1/s,
    "ascii plot with two implicit cols uses column 0 and zeroed-out column 0");
 
 eval { $w->plot(with=>'lines',xvals(5),xvals(5),{trid=>1})};
 isnt($@, '', "ascii 3-d plot with 1 implicit col fails (0 or 2 only)");
 
 eval { $w->plot(with=>'lines',xvals(5),xvals(5),xvals(5),{trid=>1}) };
 is($@, '', "ascii 3-d plot with no implicit cols succeeds");
-like($PDL::Graphics::Gnuplot::last_plotcmd, qr/plot +'-' +using 1:2:3 /s,
+like($PDL::Graphics::Gnuplot::last_plotcmd, qr/plot +\$PGG_data_\d+ +using 1:2:3 /s,
    "ascii 3-d plot with no implicit cols does the Right Thing");
 
 eval { $w->plot(with=>'lines',xvals(5,5),{trid=>1}) };