Alias ax (c) for subplot

Used to advance to the selected subplot panel. Technically only allowed when in subplot mode. See https://docs.generic-mapping-tools.org/latest/gmt.html#c-full.

Author: weiji14

pygmt/base_plotting.py

@@ -70,6 +70,7 @@ def _preprocess(self, **kwargs):  # pylint: disable=no-self-use
         W="shorelines",
         G="land",
         S="water",
+        c="ax",
     )
     @kwargs_to_strings(R="sequence")
     def coast(self, **kwargs):
@@ -146,6 +147,7 @@ def coast(self, **kwargs):
         F="box",
         G="truncate",
         W="scale",
+        c="ax",
     )
     @kwargs_to_strings(R="sequence", G="sequence")
     def colorbar(self, **kwargs):
@@ -225,6 +227,7 @@ def colorbar(self, **kwargs):
         S="resample",
         U="logo",
         W="pen",
+        c="ax",
     )
     @kwargs_to_strings(R="sequence", L="sequence", A="sequence_plus")
     def grdcontour(self, grid, **kwargs):
@@ -288,7 +291,9 @@ def grdcontour(self, grid, **kwargs):
                 lib.call_module("grdcontour", arg_str)
 
     @fmt_docstring
-    @use_alias(R="region", J="projection", W="pen", B="frame", I="shading", C="cmap")
+    @use_alias(
+        R="region", J="projection", W="pen", B="frame", I="shading", C="cmap", c="ax"
+    )
     @kwargs_to_strings(R="sequence")
     def grdimage(self, grid, **kwargs):
         """
@@ -333,6 +338,7 @@ def grdimage(self, grid, **kwargs):
         Wc="contourpen",
         Wm="meshpen",
         Wf="facadepen",
+        c="ax",
         p="perspective",
     )
     @kwargs_to_strings(R="sequence", p="sequence")
@@ -438,6 +444,7 @@ def grdview(self, grid, **kwargs):
         i="columns",
         l="label",
         C="cmap",
+        c="ax",
     )
     @kwargs_to_strings(R="sequence", i="sequence_comma")
     def plot(self, x=None, y=None, data=None, sizes=None, direction=None, **kwargs):
@@ -555,6 +562,7 @@ def plot(self, x=None, y=None, data=None, sizes=None, direction=None, **kwargs):
         L="triangular_mesh_pen",
         i="columns",
         C="levels",
+        c="ax",
     )
     @kwargs_to_strings(R="sequence", i="sequence_comma")
     def contour(self, x=None, y=None, z=None, data=None, **kwargs):
@@ -622,7 +630,7 @@ def contour(self, x=None, y=None, z=None, data=None, **kwargs):
                 lib.call_module("contour", arg_str)
 
     @fmt_docstring
-    @use_alias(R="region", J="projection", B="frame")
+    @use_alias(R="region", J="projection", B="frame", c="ax")
     @kwargs_to_strings(R="sequence")
     def basemap(self, **kwargs):
         """
@@ -663,7 +671,7 @@ def basemap(self, **kwargs):
             lib.call_module("basemap", build_arg_string(kwargs))
 
     @fmt_docstring
-    @use_alias(R="region", J="projection")
+    @use_alias(R="region", J="projection", c="ax")
     @kwargs_to_strings(R="sequence")
     def logo(self, **kwargs):
         """
@@ -698,7 +706,7 @@ def logo(self, **kwargs):
             lib.call_module("logo", build_arg_string(kwargs))
 
     @fmt_docstring
-    @use_alias(R="region", J="projection")
+    @use_alias(R="region", J="projection", c="ax")
     @kwargs_to_strings(R="sequence")
     def image(self, imagefile, **kwargs):
         """
@@ -733,7 +741,7 @@ def image(self, imagefile, **kwargs):
             lib.call_module("image", arg_str)
 
     @fmt_docstring
-    @use_alias(R="region", J="projection", D="position", F="box")
+    @use_alias(R="region", J="projection", D="position", F="box", c="ax")
     @kwargs_to_strings(R="sequence")
     def legend(self, spec=None, position="JTR+jTR+o0.2c", box="+gwhite+p1p", **kwargs):
         """
@@ -788,7 +796,7 @@ def legend(self, spec=None, position="JTR+jTR+o0.2c", box="+gwhite+p1p", **kwarg
             lib.call_module("legend", arg_str)
 
     @fmt_docstring
-    @use_alias(R="region", J="projection", B="frame")
+    @use_alias(R="region", J="projection", B="frame", c="ax")
     @kwargs_to_strings(
         R="sequence",
         textfiles="sequence_space",

pygmt/figure.py

@@ -421,7 +421,7 @@ def sca(self, ax=None, **kwargs):
         """
         arg_str = " ".join(["set", f"{ax}", build_arg_string(kwargs)])
         with Session() as lib:
-            lib.call_module(module=f"subplot", args=arg_str)
+            lib.call_module(module="subplot", args=arg_str)
 
     @fmt_docstring
     @use_alias(V="verbose")

pygmt/tests/baseline/test_subplot_direct.png

@@ -32,3 +32,15 @@ def test_subplot_frame():
     fig.basemap(region=[0, 3, 0, 3], frame="+tplot1")
     fig.end_subplot()
     return fig
+
+
+@pytest.mark.mpl_image_compare
+def test_subplot_direct():
+    """
+    Plot map elements to subplots directly using ax argument
+    """
+    fig, axs = subplots(nrows=2, ncols=1, figsize=("3c", "6c"))
+    fig.basemap(region=[0, 3, 0, 3], frame=True, ax=axs[0, 0])
+    fig.basemap(region=[0, 3, 0, 3], frame=True, ax=axs[1, 0])
+    fig.end_subplot()
+    return fig