plot/plot3d: Simplify the -A syntax to -Ax|y

doc/rst/source/explain_line_draw.rst_

@@ -1,15 +1,16 @@
-**-A**\ [**m**\|\ **p**\|\ **x**\|\ **y**\|\ **r**\|\ **t**]
+**-A**\ [**x**\|\ **y**]
     By default, geographic line segments are drawn as great circle arcs by resampling
     coarse input data along such arcs. To disable this sampling and draw them as
     straight lines, use the |-A| flag.  For Cartesian data, points are simply connected.
     To adjust these behaviors, append a directive:
 
-    - **m** - Draw the line by first following a meridian, then a parallel.
-    - **p** - Start following a parallel, then a meridian. (This can be practical
-      to draw a line along parallels, for example).
-    - **r** - For polar projections, draw stair-case curves whose first move is along *r*.
-    - **t** - Same, but first move is along *theta*.
-    - **x** - For Cartesian data, draw stair-case curves that whose first move is along *x*.
-    - **y** - Same, but first move is along *y*.
+    - **x** - First follow *x*, then *y* for staircase curves.
+    - **y** - First follow *y*, then *x* for staircase curves.
+
+    Here, *x* and *y* have the following meanings:
+
+    - For Cartesian projections, *x* and *y* are the X- and Y-axis.
+    - For gragraphic projections, *x* and *y* are parallels and meridians.
+    - For polar projections, *x* and *y* are theta and radius.
 
     **Note**: In :doc:`plot3d`, the |-A| option requires constant *z*-coordinates.

doc/rst/source/plot.rst

@@ -14,7 +14,7 @@ Synopsis
 
 **gmt plot** [ *table* ] |-J|\ *parameters*
 |SYN_OPT-Rz|
-[ |-A|\ [**m**\|\ **p**\|\ **x**\|\ **y**\|\ **r**\|\ **t**] ]
+[ |-A|\ [**x**\|\ **y**] ]
 [ |SYN_OPT-B| ]
 [ |-C|\ *cpt* ]
 [ |-D|\ *dx*\ [/*dy*] ]
@@ -249,13 +249,13 @@ Optional Arguments
       as column 2 (i.e., third) in any number of files having three columns. Each file may
       contain any number of segments per file.
     - **s** - Same but the two curves are given via separate pairs of tables [Default].
-    
+
     Several modifiers are at your disposal:
 
     - **+g** - We use the *fill* set via |-G| to fill the areas where :math:`y_0(x)` exceeds
-      :math:`y_1(x)`. For the opposite case, append another *fill* here.  
+      :math:`y_1(x)`. For the opposite case, append another *fill* here.
     - **+l** - For the primary curve :math:`y_0(x)`, a legend label can be set via option
-      |SYN_OPT-l|. For a secondary label use this modifier to append the label.  
+      |SYN_OPT-l|. For a secondary label use this modifier to append the label.
     - **+p** - Specify a separate pen for drawing curve :math:`y_1(x)` [Default is same pen
       as :math:`y_0(x)`]. See |-W| for specifying the pen for curve :math:`y_0(x)`.
     - **+r** - Specify a pen to simply draw a line instead of a filled box in the legend, but
@@ -309,7 +309,7 @@ Optional Arguments
     *width* = 0.25p, *color* = black, *style* = solid]. Modifiers can be used to change the
     appearance of the line:
 
-    - **+c** - Determine how the color from the cpt file lookup is applied to symbol 
+    - **+c** - Determine how the color from the cpt file lookup is applied to symbol
       and|or fill.  Append **l** to have the color of the line to be taken from the CPT (see
       |-C|). If instead **f** is appended then the color from the cpt file is applied
       to symbol fill.  If no argument is given the we use the color for both pen and fill.

doc/rst/source/plot3d.rst

@@ -15,7 +15,7 @@ Synopsis
 **gmt plot3d** [ *table* ] |-J|\ *parameters*
 |-Jz|\ \|\ **Z**\ *parameters*
 |SYN_OPT-Rz|
-[ |-A|\ [**m**\|\ **p**\|\ **x**\|\ **y**\|\ **r**\|\ **t**] ]
+[ |-A|\ [**x**\|\ **y**] ]
 [ |SYN_OPT-B| ]
 [ |-C|\ *cpt* ]
 [ |-D|\ *dx*/*dy*\ [/*dz*] ]
@@ -211,7 +211,7 @@ Optional Arguments
     *width* = 0.25p, *color* = black, *style* = solid]. Modifiers can be used to change the
     appearance of the line:
 
-    - **+c** - Determine how the color from the cpt file lookup is applied to symbol 
+    - **+c** - Determine how the color from the cpt file lookup is applied to symbol
       and|or fill.  Append **l** to have the color of the line to be taken from the CPT (see
       |-C|). If instead **f** is appended then the color from the cpt file is applied
       to symbol fill.  If no argument is given the we use the color for both pen and fill.

doc/rst/source/psxy.rst

@@ -14,7 +14,7 @@ Synopsis
 
 **gmt psxy** [ *table* ] |-J|\ *parameters*
 |SYN_OPT-Rz|
-[ |-A|\ [**m**\|\ **p**\|\ **x**\|\ **y**\|\ **r**\|\ **t**] ]
+[ |-A|\ [**x**\|\ **y**] ]
 [ |SYN_OPT-B| ]
 [ |-C|\ *cpt* ]
 [ |-D|\ *dx*/*dy* ]

doc/rst/source/psxyz.rst

@@ -15,7 +15,7 @@ Synopsis
 **gmt psxyz** [ *table* ] |-J|\ *parameters*
 |-J|\ **z**\|\ **Z**\ *parameters*
 |SYN_OPT-Rz|
-[ |-A|\ [**m**\|\ **p**\|\ **x**\|\ **y**\|\ **r**\|\ **t**] ]
+[ |-A|\ [**x**\|\ **y**] ]
 [ |SYN_OPT-B| ]
 [ |-C|\ *cpt* ]
 [ |-D|\ *dx*/*dy*\ [/*dz*] ]

src/psxy.c

@@ -43,7 +43,7 @@
 
 struct PSXY_CTRL {
 	bool no_RJ_needed;	/* Special case of -T and no -B when -R -J is not required */
-	struct PSXY_A {	/* -A[m|y|p|x|r|t<step>] */
+	struct PSXY_A {	/* -A[x|y]] */
 		bool active;
 		unsigned int mode;
 		double step;
@@ -529,7 +529,7 @@ static int usage (struct GMTAPI_CTRL *API, int level) {
 	const char *mod_name = &name[4];	/* To skip the leading gmt for usage messages */
 	if (level == GMT_MODULE_PURPOSE) return (GMT_NOERROR);
 
-	GMT_Usage (API, 0, "usage: %s [<table>] %s %s [-A[m|p|r|t|x|y]] [%s] [-C<cpt>] [-D<dx>/<dy>] [%s] [-F%s] [-G<fill>|+z] "
+	GMT_Usage (API, 0, "usage: %s [<table>] %s %s [-A[x|y]] [%s] [-C<cpt>] [-D<dx>/<dy>] [%s] [-F%s] [-G<fill>|+z] "
 		"[-H[<scale>]] [-I[<intens>]] %s[%s] [-M[c|s][+g<fill>][+l<seclabel>][+p<pen>][+r[<pen>]][+y[<level>]]] [-N[c|r]] %s%s [-S[<symbol>][<size>]] [%s] [%s] [-W[<pen>][<attr>]] [%s] [%s] "
 		"[-Z<value>|<file>[+t|T]] [%s] [%s] %s[%s] [%s] [%s] [%s] [%s] [%s] [%s] [%s] [%s] [%s] [%s] [%s] [%s]\n",
 		name, GMT_J_OPT, GMT_Rgeoz_OPT, GMT_B_OPT, PSXY_E_OPT, GMT_SEGMENTIZE3, API->K_OPT, PLOT_L_OPT, API->O_OPT, API->P_OPT,
@@ -542,15 +542,15 @@ static int usage (struct GMTAPI_CTRL *API, int level) {
 	GMT_Message (API, GMT_TIME_NONE, "  REQUIRED ARGUMENTS:\n");
 	GMT_Option (API, "<,J-Z,R");
 	GMT_Message (API, GMT_TIME_NONE, "\n  OPTIONAL ARGUMENTS:\n");
-	GMT_Usage (API, 1, "\n-A[m|p|r|t|x|y]");
+	GMT_Usage (API, 1, "\n-A[x|y]");
 	GMT_Usage (API, -2, "Suppress drawing geographic line segments as great circle arcs, i.e., draw "
-		"straight lines instead.  Six optional directives instead convert paths to staircase curves:");
-	GMT_Usage (API, 3, "m: First follow meridians, then parallels when connecting geographic points.");
-	GMT_Usage (API, 3, "p: First follow parallels, then meridians when connecting geographic point.");
-	GMT_Usage (API, 3, "r: First follow radius, then theta for staircase curves for Polar projection.");
-	GMT_Usage (API, 3, "t: First follow theta, then radius for staircase curves for Polar projection.");
-	GMT_Usage (API, 3, "x: First follow x, then y for staircase curves for Cartesian projections.");
-	GMT_Usage (API, 3, "y: First follow y, then x for staircase curves for Cartesian projections.");
+		"straight lines instead. Two optional directives instead convert paths to staircase curves:");
+	GMT_Usage (API, 3, "x: First follow x, then y for staircase curves.");
+	GMT_Usage (API, 3, "y: First follow y, then x for staircase curves.");
+	GMT_Usage (API, -2, "Here, x and y have the following meanings: "
+		"For Cartesian projections, x and y are the X- and Y-axis; "
+		"For gragraphic projections, x and y are parallels and meridians; "
+		"For polar projections, x and y are theta and radius.");
 	GMT_Option (API, "B-");
 	GMT_Usage (API, 1, "\n-C<cpt>|<color1>,<color2>[,<color3>,...]");
 	GMT_Usage (API, -2, "Assign symbol colors based on z-value in 3rd column. "
@@ -837,6 +837,7 @@ static int parse (struct GMT_CTRL *GMT, struct PSXY_CTRL *Ctrl, struct GMT_OPTIO
 
 			case 'A':	/* Turn off draw_arc mode */
 				n_errors += gmt_M_repeated_module_option (API, Ctrl->A.active);
+				/* There are 6 optional directives but only x|y are documented since 6.6.0 */
 				switch (opt->arg[0]) {
 					case 'm': case 'y': case 'r': Ctrl->A.mode = GMT_STAIRS_Y; break;
 					case 'p': case 'x': case 't': Ctrl->A.mode = GMT_STAIRS_X; break;

src/psxyz.c

@@ -40,7 +40,7 @@
 /* Control structure for psxyz */
 
 struct PSXYZ_CTRL {
-	struct PSXYZ_A {	/* -A[m|y|p|x|r|t|step] */
+	struct PSXYZ_A {	/* -A[x|y] */
 		bool active;
 		unsigned int mode;
 		double step;
@@ -173,7 +173,7 @@ static int usage (struct GMTAPI_CTRL *API, int level) {
 	const char *mod_name = &name[4];	/* To skip the leading gmt for usage messages */
 	const char *T[2] = {" [-T]", ""};
 	if (level == GMT_MODULE_PURPOSE) return (GMT_NOERROR);
-	GMT_Usage (API, 0, "usage: %s [<table>] %s %s [%s] [%s] [-A[m|p|r|t|x|y]] [-C<cpt>] [-D<dx>/<dy>[/<dz>]] [-G<fill>] "
+	GMT_Usage (API, 0, "usage: %s [<table>] %s %s [%s] [%s] [-A[x|y]] [-C<cpt>] [-D<dx>/<dy>[/<dz>]] [-G<fill>] "
 		"[-H[<scale>]] [-I[<intens>]] %s [%s] [-N[c|r]] %s %s[-Q] [-S[<symbol>][<size>][/size_y]]%s [%s] [%s] [-W[<pen>][<attr>]] "
 		"[%s] [%s] [-Z<value>|<file>[+t|T]] [%s] [%s] %s[%s] [%s] [%s] [%s] [%s] [%s] [%s] [%s] [%s] [%s] [%s] [%s] [%s]\n",
 		name, GMT_J_OPT, GMT_Rgeoz_OPT, GMT_B_OPT, GMT_Jz_OPT, API->K_OPT, PLOT_L_OPT, API->O_OPT, API->P_OPT,
@@ -187,15 +187,15 @@ static int usage (struct GMTAPI_CTRL *API, int level) {
 	GMT_Option (API, "<,J-Z,R3");
 	GMT_Message (API, GMT_TIME_NONE, "\n  OPTIONAL ARGUMENTS:\n");
 	GMT_Option (API, "B-");
-	GMT_Usage (API, 1, "\n-A[m|p|r|t|x|y]");
+	GMT_Usage (API, 1, "\n-A[x|y]");
 	GMT_Usage (API, -2, "Suppress drawing geographic line segments as great circle arcs, i.e., draw "
-		"straight lines instead.  Six optional directives instead convert paths to staircase curves:");
-	GMT_Usage (API, 3, "m: First follow meridians, then parallels when connecting geographic points.");
-	GMT_Usage (API, 3, "p: First follow parallels, then meridians when connecting geographic point.");
-	GMT_Usage (API, 3, "r: First follow radius, then theta for staircase curves for Polar projection.");
-	GMT_Usage (API, 3, "t: First follow theta, then radius for staircase curves for Polar projection.");
-	GMT_Usage (API, 3, "x: First follow x, then y for staircase curves for Cartesian projections.");
-	GMT_Usage (API, 3, "y: First follow y, then x for staircase curves for Cartesian projections.");
+		"straight lines instead. Two optional directives instead convert paths to staircase curves:");
+	GMT_Usage (API, 3, "x: First follow x, then y for staircase curves.");
+	GMT_Usage (API, 3, "y: First follow y, then x for staircase curves.");
+	GMT_Usage (API, -2, "Here, x and y have the following meanings: "
+		"For Cartesian projections, x and y are the X- and Y-axis; "
+		"For gragraphic projections, x and y are parallels and meridians; "
+		"For polar projections, x and y are theta and radius.");
 	GMT_Usage (API, 1, "\n-C<cpt>|<color1>,<color2>[,<color3>,...]");
 	GMT_Usage (API, -2, "Assign symbol colors based on z-value in 3rd column. "
 		"Note: requires -S. Without -S, %s excepts lines/polygons "
@@ -422,6 +422,7 @@ static int parse (struct GMT_CTRL *GMT, struct PSXYZ_CTRL *Ctrl, struct GMT_OPTI
 
 			case 'A':	/* Turn off draw_arc mode */
 				n_errors += gmt_M_repeated_module_option (API, Ctrl->A.active);
+				/* There are 6 optional directives but only x|y are documented since 6.6.0 */
 				switch (opt->arg[0]) {
 					case 'm': case 'y': case 'r': Ctrl->A.mode = GMT_STAIRS_Y; break;
 					case 'p': case 'x': case 't': Ctrl->A.mode = GMT_STAIRS_X; break;

test/psxy/nojump.sh

@@ -12,5 +12,5 @@ cat << EOF > t.txt
 115 -20
 EOF
 gmt psxy -R110/215/-27/20 -JM6i t.txt -Wfat,green -Baf -BWSne -A -P -K -Xc > $ps
-gmt psxy -R -J t.txt -Wfat,green -Baf -BWSne -Ap -O -K -Y3.15i >> $ps
+gmt psxy -R -J t.txt -Wfat,green -Baf -BWSne -Ax -O -K -Y3.15i >> $ps
 gmt psxy -R -J t.txt -Wfat,green -Baf -BWSne -O -Y3.15i >> $ps

test/psxy/polarcurves.sh

@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-# test the -Ar|t line-resampling for polar projections
+# test the -Ax|y line-resampling for polar projections
 cat << EOF > t.txt
 10  5
 30 4
@@ -10,11 +10,11 @@ gmt begin polarcurves ps
 		gmt subplot set 0 -A"No -A"
 		gmt plot -W2p,red t.txt
 		gmt plot t.txt -Sc0.2c -Wthin
-		gmt subplot set 1 -A"-At: @~q@~, then r"
-		gmt plot -W2p,red -At t.txt
+		gmt subplot set 1 -A"-Ax: @~q@~, then r"
+		gmt plot -W2p,red -Ax t.txt
 		gmt plot t.txt -Sc0.2c -Wthin
-		gmt subplot set 2 -A"-Ar: r, then @~q@~"
-		gmt plot -W2p,red -Ar t.txt
+		gmt subplot set 2 -A"-Ay: r, then @~q@~"
+		gmt plot -W2p,red -Ay t.txt
 		gmt plot t.txt -Sc0.2c -Wthin
 	gmt subplot end
 gmt end show