Change load_earth_relief()'s default resolution to 01d (#488)

In GMT 6.0.0, both `01d` and `60m` are valid resolutions of earth
relief data. It was called `60m` at the beginning and was changed to `01d`
when GMT 6.0.0 was officially released. `60m` is still valid for backward
compatibility.

Run the following commands, and you will have the two data in the
current directory.
```
gmt which @earth_relief_60m -Gl
gmt which @earth_relief_01d -Gl
```
These two files have different file names but are identical:
```
$ md5sum earth_relief_01d.grd earth_relief_60m.grd
74a884c902015dda516d17605f317efe  earth_relief_01d.grd
74a884c902015dda516d17605f317efe  earth_relief_60m.grd
```

In the upcoming GMT 6.1.0, the resolution `60m` will be deprecated.
That's why we have many ~25 errors when testing PyGMT with the GMT master
branch, simply because GMT 6.1.0 can't download the `@earth_relief_60m`.

To make the transition to GMT 6.1.0 easier, here I change the default
earth relief resolution of `load_earth_relief()` function from `60m` to
`01d`. As the two grids are identical, the change in this PR won't break
anything.

Note that, currently there are ~43 failures due to the recent updates of
the GMT data server (#451), and we can't fix these failures easily due
to the grid registration issue (#476). Thus, I don't try to fix any
failures in this PR.

The test log files of the master branch and this branch are the same.
Tests that fail in the master branch still fail in the same way in this branch.

Co-authored-by: Wei Ji <[email protected]>

.azure-pipelines.yml

@@ -128,7 +128,7 @@ jobs:
   - bash: |
       set -x -e
       source activate testing
-      gmt which -Gu @earth_relief_10m @earth_relief_60m @ridge.txt @Table_5_11.txt @tut_bathy.nc @tut_quakes.ngdc @tut_ship.xyz
+      gmt which -Gu @earth_relief_10m @earth_relief_01d @ridge.txt @Table_5_11.txt @tut_bathy.nc @tut_quakes.ngdc @tut_ship.xyz
     displayName: Download remote data
     condition: ne(variables['CACHE_CACHEDATA_RESTORED'], true)
 
@@ -224,7 +224,7 @@ jobs:
   - bash: |
       set -x -e
       source activate testing
-      gmt which -Gu @earth_relief_10m @earth_relief_60m @ridge.txt @Table_5_11.txt @tut_bathy.nc @tut_quakes.ngdc @tut_ship.xyz
+      gmt which -Gu @earth_relief_10m @earth_relief_01d @ridge.txt @Table_5_11.txt @tut_bathy.nc @tut_quakes.ngdc @tut_ship.xyz
     displayName: Download remote data
     condition: ne(variables['CACHE_CACHEDATA_RESTORED'], true)
 

pygmt/clib/conversion.py

@@ -46,8 +46,8 @@ def dataarray_to_matrix(grid):
     --------
 
     >>> from pygmt.datasets import load_earth_relief
-    >>> # Use the global Earth relief grid with 1 degree spacing (60')
-    >>> grid = load_earth_relief(resolution='60m')
+    >>> # Use the global Earth relief grid with 1 degree spacing
+    >>> grid = load_earth_relief(resolution='01d')
     >>> matrix, region, inc = dataarray_to_matrix(grid)
     >>> print(region)
     [-180.0, 180.0, -90.0, 90.0]

pygmt/clib/session.py

@@ -1210,7 +1210,7 @@ def virtualfile_from_grid(self, grid):
 
         >>> from pygmt.datasets import load_earth_relief
         >>> from pygmt.helpers import GMTTempFile
-        >>> data = load_earth_relief(resolution='60m')
+        >>> data = load_earth_relief(resolution='01d')
         >>> print(data.shape)
         (181, 361)
         >>> print(data.lon.values.min(), data.lon.values.max())

pygmt/datasets/earth_relief.py

@@ -8,7 +8,7 @@
 from ..exceptions import GMTInvalidInput
 
 
-def load_earth_relief(resolution="60m"):
+def load_earth_relief(resolution="01d"):
     """
     Load Earth relief grids (topography and bathymetry) in various resolutions.
 
@@ -23,9 +23,10 @@ def load_earth_relief(resolution="60m"):
     Parameters
     ----------
     resolution : str
-        The grid resolution. The suffix ``m`` and ``s`` stand for arc-minute
-        and arc-second. It can be ``'60m'``, ``'30m'``, ``'10m'``, ``'05m'``,
-        ``'02m'``, ``'01m'``, ``'30s'`` or ``'15s'``.
+        The grid resolution. The suffix ``d``, ``m`` and ``s`` stand for
+        arc-degree, arc-minute and arc-second. It can be ``'01d'``, ``'30m'``,
+        ``'20m'``, ``'15m'``, ``'10m'``, ``'06m'``, ``'05m'``, ``'04m'``,
+        ``'03m'``, ``'02m'``, ``'01m'``, ``'30s'`` or ``'15s'``.
 
     Returns
     -------
@@ -69,6 +70,7 @@ def _is_valid_resolution(resolution):
     Examples
     --------
 
+    >>> _is_valid_resolution("01d")
     >>> _is_valid_resolution("60m")
     >>> _is_valid_resolution("5m")
     Traceback (most recent call last):
@@ -81,8 +83,11 @@ def _is_valid_resolution(resolution):
     pygmt.exceptions.GMTInvalidInput: Invalid Earth relief resolution '01s'.
 
     """
-    valid_resolutions = ["{:02d}m".format(res) for res in [60, 30, 10, 5, 2, 1]]
-    valid_resolutions.extend(["{:02d}s".format(res) for res in [30, 15]])
+    valid_resolutions = ["01d"]
+    valid_resolutions.extend(
+        [f"{res:02d}m" for res in [60, 30, 20, 15, 10, 6, 5, 4, 3, 2, 1]]
+    )
+    valid_resolutions.extend([f"{res:02d}s" for res in [30, 15]])
     if resolution not in valid_resolutions:
         raise GMTInvalidInput(
             "Invalid Earth relief resolution '{}'.".format(resolution)
@@ -120,7 +125,9 @@ def _shape_from_resolution(resolution):
     """
     _is_valid_resolution(resolution)
     unit = resolution[2]
-    if unit == "m":
+    if unit == "d":
+        seconds = int(resolution[:2]) * 60 * 60
+    elif unit == "m":
         seconds = int(resolution[:2]) * 60
     elif unit == "s":
         seconds = int(resolution[:2])

pygmt/tests/test_datasets.py

@@ -67,18 +67,18 @@ def test_earth_relief_fails():
             load_earth_relief(resolution=resolution)
 
 
-# Only test 60m and 30m to avoid downloading large datasets in CI
-def test_earth_relief_60():
-    "Test some properties of the earth relief 60m data"
-    data = load_earth_relief(resolution="60m")
+# Only test 01d and 30m to avoid downloading large datasets in CI
+def test_earth_relief_01d():
+    "Test some properties of the earth relief 01d data"
+    data = load_earth_relief(resolution="01d")
     assert data.shape == (181, 361)
     npt.assert_allclose(data.lat, np.arange(-90, 91, 1))
     npt.assert_allclose(data.lon, np.arange(-180, 181, 1))
     npt.assert_allclose(data.min(), -8592.144531)
     npt.assert_allclose(data.max(), 5558.79248)
 
 
-def test_earth_relief_30():
+def test_earth_relief_30m():
     "Test some properties of the earth relief 30m data"
     data = load_earth_relief(resolution="30m")
     assert data.shape == (361, 721)

pygmt/tests/test_grdcontour.py

@@ -58,7 +58,7 @@ def test_grdcontour_file():
     "Plot a contour image using grid file input"
     fig = Figure()
     fig.grdcontour(
-        "@earth_relief_60m",
+        "@earth_relief_01d",
         interval="1000",
         limit="0",
         pen="0.5p,black",

pygmt/tests/test_grdimage.py

@@ -32,7 +32,7 @@ def test_grdimage_file():
     "Plot an image using file input"
     fig = Figure()
     fig.grdimage(
-        "@earth_relief_60m",
+        "@earth_relief_01d",
         cmap="ocean",
         region=[-180, 180, -70, 70],
         projection="W0/10i",

pygmt/tests/test_grdinfo.py

@@ -18,7 +18,7 @@ def test_grdinfo():
 
 def test_grdinfo_file():
     "Test grdinfo with file input"
-    result = grdinfo("@earth_relief_60m", L=0, C="n")
+    result = grdinfo("@earth_relief_01d", L=0, C="n")
     assert result.strip() == "-180 180 -90 90 -8592.14465255 5558.79248047 1 1 361 181"
 
 

pygmt/tests/test_grdtrack.py

@@ -58,7 +58,7 @@ def test_grdtrack_input_dataframe_and_ncfile():
     Run grdtrack by passing in a pandas.DataFrame and netcdf file as inputs
     """
     dataframe = load_ocean_ridge_points()
-    ncfile = which("@earth_relief_60m", download="c")
+    ncfile = which("@earth_relief_01d", download="c")
 
     output = grdtrack(points=dataframe, grid=ncfile, newcolname="bathymetry")
     assert isinstance(output, pd.DataFrame)
@@ -73,7 +73,7 @@ def test_grdtrack_input_csvfile_and_ncfile():
     Run grdtrack by passing in a csvfile and netcdf file as inputs
     """
     csvfile = which("@ridge.txt", download="c")
-    ncfile = which("@earth_relief_60m", download="c")
+    ncfile = which("@earth_relief_01d", download="c")
 
     try:
         output = grdtrack(points=csvfile, grid=ncfile, outfile=TEMP_TRACK)

pygmt/tests/test_grdview.py

@@ -31,7 +31,7 @@ def test_grdview_grid_file_with_region_subset():
     """
     Run grdview by passing in a grid filename, and cropping it to a region.
     """
-    gridfile = which("@earth_relief_60m", download="c")
+    gridfile = which("@earth_relief_01d", download="c")
 
     fig = Figure()
     fig.grdview(grid=gridfile, region=[-116, -109, -47, -44])