_load_remote_dataset: Add the "kind" attribute to explicitly specify if data is a grid or image (#3688)

Author: seisman

pygmt/datasets/load_remote_dataset.py

@@ -39,7 +39,9 @@ class GMTRemoteDataset(NamedTuple):
     Attributes
     ----------
     description
-       The name assigned as an attribute to the DataArray.
+        The name assigned as an attribute to the DataArray.
+    kind
+        The kind of the dataset source. Valid values are ``"grid"`` and ``"image"``.
     units
         The units of the values in the DataArray.
     resolutions
@@ -49,6 +51,7 @@ class GMTRemoteDataset(NamedTuple):
     """
 
     description: str
+    kind: Literal["grid", "image"]
     units: str | None
     resolutions: dict[str, Resolution]
     extra_attributes: dict[str, Any]
@@ -57,6 +60,7 @@ class GMTRemoteDataset(NamedTuple):
 datasets = {
     "earth_age": GMTRemoteDataset(
         description="EarthByte Earth seafloor crustal age",
+        kind="grid",
         units="Myr",
         extra_attributes={"horizontal_datum": "WGS84"},
         resolutions={
@@ -75,6 +79,7 @@ class GMTRemoteDataset(NamedTuple):
     ),
     "earth_day": GMTRemoteDataset(
         description="NASA Day Images",
+        kind="image",
         units=None,
         extra_attributes={"long_name": "blue_marble", "horizontal_datum": "WGS84"},
         resolutions={
@@ -94,6 +99,7 @@ class GMTRemoteDataset(NamedTuple):
     ),
     "earth_dist": GMTRemoteDataset(
         description="GSHHG Earth distance to shoreline",
+        kind="grid",
         units="kilometers",
         extra_attributes={"horizontal_datum": "WGS84"},
         resolutions={
@@ -112,6 +118,7 @@ class GMTRemoteDataset(NamedTuple):
     ),
     "earth_edefl": GMTRemoteDataset(
         description="IGPP Earth east-west deflection",
+        kind="grid",
         units="micro-radians",
         extra_attributes={"horizontal_datum": "WGS84"},
         resolutions={
@@ -130,6 +137,7 @@ class GMTRemoteDataset(NamedTuple):
     ),
     "earth_faa": GMTRemoteDataset(
         description="IGPP Earth free-air anomaly",
+        kind="grid",
         units="mGal",
         extra_attributes={"horizontal_datum": "WGS84"},
         resolutions={
@@ -148,6 +156,7 @@ class GMTRemoteDataset(NamedTuple):
     ),
     "earth_faaerror": GMTRemoteDataset(
         description="IGPP Earth free-air anomaly errors",
+        kind="grid",
         units="mGal",
         extra_attributes={"horizontal_datum": "WGS84"},
         resolutions={
@@ -166,6 +175,7 @@ class GMTRemoteDataset(NamedTuple):
     ),
     "earth_gebco": GMTRemoteDataset(
         description="GEBCO Earth relief",
+        kind="grid",
         units="meters",
         extra_attributes={"vertical_datum": "EGM96", "horizontal_datum": "WGS84"},
         resolutions={
@@ -188,6 +198,7 @@ class GMTRemoteDataset(NamedTuple):
     ),
     "earth_geoid": GMTRemoteDataset(
         description="EGM2008 Earth geoid",
+        kind="grid",
         units="meters",
         extra_attributes={"horizontal_datum": "WGS84"},
         resolutions={
@@ -206,6 +217,7 @@ class GMTRemoteDataset(NamedTuple):
     ),
     "earth_igpp": GMTRemoteDataset(
         description="IGPP Earth relief",
+        kind="grid",
         units="meters",
         extra_attributes={"vertical_datum": "EGM96", "horizontal_datum": "WGS84"},
         resolutions={
@@ -228,6 +240,7 @@ class GMTRemoteDataset(NamedTuple):
     ),
     "earth_mag": GMTRemoteDataset(
         description="EMAG2 Earth Magnetic Anomaly Model",
+        kind="grid",
         units="nT",
         extra_attributes={"horizontal_datum": "WGS84"},
         resolutions={
@@ -245,6 +258,7 @@ class GMTRemoteDataset(NamedTuple):
     ),
     "earth_mask": GMTRemoteDataset(
         description="GSHHG Earth mask",
+        kind="grid",
         units=None,
         extra_attributes={"horizontal_datum": "WGS84"},
         resolutions={
@@ -265,6 +279,7 @@ class GMTRemoteDataset(NamedTuple):
     ),
     "earth_mss": GMTRemoteDataset(
         description="CNES Earth mean sea surface",
+        kind="grid",
         units="meters",
         extra_attributes={"horizontal_datum": "WGS84"},
         resolutions={
@@ -283,6 +298,7 @@ class GMTRemoteDataset(NamedTuple):
     ),
     "earth_night": GMTRemoteDataset(
         description="NASA Night Images",
+        kind="image",
         units=None,
         extra_attributes={"long_name": "black_marble", "horizontal_datum": "WGS84"},
         resolutions={
@@ -302,6 +318,7 @@ class GMTRemoteDataset(NamedTuple):
     ),
     "earth_mdt": GMTRemoteDataset(
         description="CNES Earth mean dynamic topography",
+        kind="grid",
         units="meters",
         extra_attributes={"horizontal_datum": "WGS84"},
         resolutions={
@@ -315,6 +332,7 @@ class GMTRemoteDataset(NamedTuple):
     ),
     "earth_ndefl": GMTRemoteDataset(
         description="IGPP Earth north-south deflection",
+        kind="grid",
         units="micro-radians",
         extra_attributes={"horizontal_datum": "WGS84"},
         resolutions={
@@ -333,6 +351,7 @@ class GMTRemoteDataset(NamedTuple):
     ),
     "earth_vgg": GMTRemoteDataset(
         description="IGPP Earth vertical gravity gradient",
+        kind="grid",
         units="Eotvos",
         extra_attributes={"horizontal_datum": "WGS84"},
         resolutions={
@@ -351,6 +370,7 @@ class GMTRemoteDataset(NamedTuple):
     ),
     "earth_wdmam": GMTRemoteDataset(
         description="WDMAM World Digital Magnetic Anomaly Map",
+        kind="grid",
         units="nT",
         extra_attributes={"horizontal_datum": "WGS84"},
         resolutions={
@@ -367,6 +387,7 @@ class GMTRemoteDataset(NamedTuple):
     ),
     "mars_relief": GMTRemoteDataset(
         description="NASA Mars (MOLA) relief",
+        kind="grid",
         units="meters",
         extra_attributes={},
         resolutions={
@@ -388,6 +409,7 @@ class GMTRemoteDataset(NamedTuple):
     ),
     "moon_relief": GMTRemoteDataset(
         description="USGS Moon (LOLA) relief",
+        kind="grid",
         units="meters",
         extra_attributes={},
         resolutions={
@@ -409,6 +431,7 @@ class GMTRemoteDataset(NamedTuple):
     ),
     "mercury_relief": GMTRemoteDataset(
         description="USGS Mercury relief",
+        kind="grid",
         units="meters",
         extra_attributes={},
         resolutions={
@@ -428,6 +451,7 @@ class GMTRemoteDataset(NamedTuple):
     ),
     "pluto_relief": GMTRemoteDataset(
         description="USGS Pluto relief",
+        kind="grid",
         units="meters",
         extra_attributes={},
         resolutions={
@@ -447,6 +471,7 @@ class GMTRemoteDataset(NamedTuple):
     ),
     "venus_relief": GMTRemoteDataset(
         description="NASA Magellan Venus relief",
+        kind="grid",
         units="meters",
         extra_attributes={},
         resolutions={
@@ -545,15 +570,16 @@ def _load_remote_dataset(
         raise GMTInvalidInput(msg)
 
     fname = f"@{prefix}_{resolution}_{reg}"
-    kind = "image" if name in {"earth_day", "earth_night"} else "grid"
-    kwdict = {"R": region, "T": {"grid": "g", "image": "i"}[kind]}
+    kwdict = {"R": region, "T": {"grid": "g", "image": "i"}[dataset.kind]}
     with Session() as lib:
-        with lib.virtualfile_out(kind=kind) as voutgrd:
+        with lib.virtualfile_out(kind=dataset.kind) as voutgrd:
             lib.call_module(
                 module="read",
                 args=[fname, voutgrd, *build_arg_list(kwdict)],
             )
-            grid = lib.virtualfile_to_raster(kind=kind, outgrid=None, vfname=voutgrd)
+            grid = lib.virtualfile_to_raster(
+                kind=dataset.kind, outgrid=None, vfname=voutgrd
+            )
 
     # Full path to the grid if not tiled grids.
     source = which(fname, download="a") if not resinfo.tiled else None