Add test_dimfilter.py

Author: willschlitzer

pygmt/tests/test_dimfilter.py

@@ -0,0 +1,51 @@
+"""
+Tests for dimfilter.
+"""
+import os
+
+import numpy.testing as npt
+import pytest
+from pygmt import dimfilter
+from pygmt.datasets import load_earth_relief
+from pygmt.exceptions import GMTInvalidInput
+from pygmt.helpers import GMTTempFile
+
+
+@pytest.fixture(scope="module", name="grid")
+def fixture_grid():
+    """
+    Load the grid data from the sample earth_relief file.
+    """
+    return load_earth_relief(resolution="30m", region=[-5, 5, -5, 5])
+
+
+def test_dimfilter_outgrid(grid):
+    """
+    Test the required parameters for dimfilter with a set outgrid.
+    """
+    with GMTTempFile(suffix=".nc") as tmpfile:
+        result = dimfilter(grid=grid, outgrid=tmpfile.name, filter="m600", distance=4, sectors="l6")
+        assert result is None  # return value is None
+        assert os.path.exists(path=tmpfile.name)  # check that outgrid exists
+
+
+def test_grdgradient_no_outgrid(grid):
+    """
+    Test the required parameters for dimfilter with no set outgrid.
+    """
+    temp_grid = dimfilter(grid=grid, filter="m600", distance=4, sectors="l6")
+    assert temp_grid.dims == ("lat", "lon")
+    assert temp_grid.gmt.gtype == 1  # Geographic grid
+    assert temp_grid.gmt.registration == 1  # Pixel registration
+    npt.assert_allclose(temp_grid.min(), -5125)
+    npt.assert_allclose(temp_grid.max(), -3750.5)
+    npt.assert_allclose(temp_grid.median(), -4826.5)
+    npt.assert_allclose(temp_grid.mean(), -4789.791)
+
+def test_dimfilter_fails(grid):
+    """
+    Check that dimfilter fails correctly when sector, 
+    filters, and distance are not specified..
+    """
+    with pytest.raises(GMTInvalidInput):
+        dimfilter(grid=grid)