better plot

1 files changed, 34 insertions, 102 deletions

diff --git a/remote_plot.c b/remote_plot.c
index 3226b20..54338aa 100644
--- a/remote_plot.c
+++ b/remote_plot.c
@@ -1,8 +1,9 @@
 // references:
 // https://api.libssh.org/stable/libssh_tutorial.html
 // https://api.libssh.org/stable/libssh_tutor_guided_tour.html
-// plplot example 17
-// plplot example ext-cairo-test.c
+// http://plplot.org/documentation.php
+// http://plplot.org/examples.php
+// plplot example 0 and ext-cairo-test.c
 // https://docs.gtk.org/gtk4/class.DrawingArea.html
 // https://www.gtk.org/docs/getting-started/hello-world/
 // https://gitlab.gnome.org/GNOME/gtk/-/blob/main/demos/print-editor/print-editor.c
@@ -170,14 +171,9 @@ const char *checkbutton_names[]={
 	"0x695_BMS_Section_1_Temp"
 };
 
-// Variables for holding error return info from PLplot
-static PLINT pl_errcode;
-static char  errmsg[160];
-
 typedef struct {
 	ssh_session session;
 	sftp_session sftp;
-	PLINT id1;
 	PLFLT t[LEN];
 	PLFLT volt[LEN][VOLTLEN];
 	PLFLT temp[LEN][TEMPLEN];
@@ -348,6 +344,9 @@ int verify_knownhost(ssh_session session)
 	return 0;
 }
 
+// http://plplot.org/documentation.php
+// http://plplot.org/examples.php
+// plplot example 0 and ext-cairo-test.c
 static void draw_function (GtkDrawingArea *area,
 		cairo_t        *cr,
 		int             width,
@@ -357,108 +356,41 @@ static void draw_function (GtkDrawingArea *area,
 	//printf("draw begin\n");
 	DATA *data=user_data;
 
-	PLINT           autoy, acc;
-	PLFLT           ymin, ymax, xlab, ylab;
-	PLFLT           tmin, tmax, tjump;
-	PLINT           colbox, collab, colline[4], styline[4];
-	PLCHAR_VECTOR   legline[4];
-
-	// If db is used the plot is much more smooth. However, because of the
-	// async X behaviour, one does not have a real-time scripcharter.
-	// This is now disabled since it does not significantly improve the
-	// performance on new machines and makes it difficult to use this
-	// example non-interactively since it requires an extra pleop call after
-	// each call to plstripa.
-	//
-	//plsetopt("db", "");
-	//plsetopt("np", "");
-
-	// User sets up plot completely except for window and data
-	// Eventually settings in place when strip chart is created will be
-	// remembered so that multiple strip charts can be used simultaneously.
-	//
-
-	// Specify some reasonable defaults for ymin and ymax
-	// The plot will grow automatically if needed (but not shrink)
-
-	ymin = -0.1;
-	ymax = 0.1;
-
-	// Specify initial tmin and tmax -- this determines length of window.
-	// Also specify maximum jump in t
-	// This can accomodate adaptive timesteps
-
-	tmin  = 0.;
-	tmax  = 10.;
-	tjump = 0.3;        // percentage of plot to jump
-
-	// Axes options same as plbox.
-	// Only automatic tick generation and label placement allowed
-	// Eventually I'll make this fancier
-
-	colbox     = 1;
-	collab     = 3;
-	styline[0] = colline[0] = 2;        // pens color and line style
-	styline[1] = colline[1] = 3;
-	styline[2] = colline[2] = 4;
-	styline[3] = colline[3] = 5;
-
-	legline[0] = "voltage";                         // pens legend
-	legline[1] = "not_used";
-	legline[2] = "not_used";
-	legline[3] = "not_used";
-
-	xlab = 0.; ylab = 0.25;     // legend position
-
-	autoy = 1;                  // autoscale y
-	acc   = 1;                  // don't scrip, accumulate
+	PLFLT y[LEN];
+	PLFLT xmin = data->t[0], xmax = data->t[LEN-1], ymin = 0, ymax = 6.;
 
-	// Initialize plplot
+	for(int i=0;i<LEN;i++)
+		y[i]=data->volt[i][0];
 
 	plsdev( "extcairo" );
-	plinit();
-	pl_cmd( PLESC_DEVINIT, cr );
-
-	pladv( 0 );
-	plvsta();
-
-	// Register our error variables with PLplot
-	// From here on, we're handling all errors here
-
-	plsError( &pl_errcode, errmsg );
-
-	plstripc( &(data->id1), "bcnst", "bcnstv",
-			tmin, tmax, tjump, ymin, ymax,
-			xlab, ylab,
-			autoy, acc,
-			colbox, collab,
-			colline, styline, legline,
-			"t", "", "Strip chart demo" );
-
-	if ( pl_errcode )
-	{
-		fprintf( stderr, "%s\n", errmsg );
-		exit( 1 );
-	}
-
-	// Let plplot handle errors from here on
 
-	plsError( NULL, NULL );
+	// change to white background and black foreground, and gray color palette
+	// http://plplot.org/docbook-manual/plplot-html-5.15.0/color.html
+	// seems should be put before plinit; or need pladv(), plvpor(), plwind() for a new picture?
+	// more see example 16
+	// http://plplot.org/examples.php?demo=16
+	// /usr/share/plplot5.15.0/examples/c/x16c.c
+	plspal0("cmap0_black_on_white.pal");
+	plspal1("cmap1_gray.pal", 1);
 
-	autoy = 0;  // autoscale y
-	acc   = 1;  // accumulate
-
-	for(int i=0;i<LEN;i++)
-	{
-		//printf("t%d %f\n",i,data->t[i]);
-		//printf("buffer%d %f\n",i,data->buffer[i]);
-		plstripa( data->id1, 0, data->t[i], data->volt[i][0]);
-	}
+	// Initialize plplot
+	plinit();
+	pl_cmd( PLESC_DEVINIT, cr );
 
-	//printf("before pl free\n");
-	plstripd( data->id1 );
+	// Create a labelled box to hold the plot.
+	plenv(xmin, xmax, ymin, ymax, 0, 0);
+	pllab("Time (s)","Voltage (V)","Time vs. Voltage");
+	// Plot the data that was prepared above.
+	// plstring for scatter
+	// #(NNN) is Hershey font code, more see example 5, 6, 21
+	// #(727) is centred X symbol; other maybe useful codes: #(728)
+	// hershey font code see http://plplot.org/examples.php?demo=07 ?
+	plstring(LEN, data->t, y, "#(727)");
+	// pline for line
+	plline(LEN, data->t, y);
+
+	// Close PLplot library
 	plend();
-	//printf("draw done\n");
 }
 
 static void print_data (GtkWidget *widget, gpointer user_data)