Figure.savefig: Support PPM (.ppm) format

Author: seisman

pygmt/figure.py

@@ -263,6 +263,7 @@ def savefig(
         - JPEG (``.jpg`` or ``.jpeg``)
         - PDF (``.pdf``)
         - BMP (``.bmp``)
+        - PPM (``.ppm``)
         - TIFF (``.tif``)
         - GeoTIFF (``.tiff``)
         - EPS (``.eps``)
@@ -305,6 +306,7 @@ def savefig(
             "pdf": "f",
             "jpg": "j",
             "bmp": "b",
+            "ppm": "m",
             "eps": "e",
             "tif": "t",
             "tiff": None,  # GeoTIFF doesn't need the -T option

pygmt/tests/test_figure.py

@@ -83,7 +83,7 @@ def test_figure_savefig_exists():
     fig = Figure()
     fig.basemap(region="10/70/-300/800", projection="X3i/5i", frame="af")
     prefix = "test_figure_savefig_exists"
-    for fmt in "png pdf jpg jpeg bmp eps tif PNG JPG JPEG Png".split():
+    for fmt in "png pdf jpg jpeg bmp ppm eps tif PNG JPG JPEG Png".split():
         fname = ".".join([prefix, fmt])
         fig.savefig(fname)