Merge pull request #245 from GeoStat-Framework/gstools_latlon_fix

GSTools: support latlon models for geographic coordinates

pyproject.toml

@@ -70,7 +70,7 @@ sklearn = ["scikit-learn>=0.19"]
 test = [
     "pytest-cov>=3",
     "scikit-learn>=0.19",
-    # "gstools>=1.3,<2",
+    "gstools>=1.4,<2",
 ]
 
 [project.urls]

src/pykrige/compat_gstools.py

@@ -0,0 +1,36 @@
+# coding: utf-8
+# pylint: disable= invalid-name,  unused-import
+"""For GSTools compatibility."""
+
+# gstools
+try:
+    import gstools as gs
+
+    GSTOOLS_INSTALLED = True
+    GSTOOLS_VERSION = list(map(int, gs.__version__.split(".")[:2]))
+except ImportError:
+    gs = None
+    GSTOOLS_INSTALLED = False
+    GSTOOLS_VERSION = None
+
+
+class GSToolsException(Exception):
+    """Exception for GSTools."""
+
+
+def validate_gstools(model):
+    """Validate presence of GSTools."""
+    if not GSTOOLS_INSTALLED:
+        raise GSToolsException(
+            "GSTools needs to be installed in order to use their CovModel class."
+        )
+    if not isinstance(model, gs.CovModel):
+        raise GSToolsException(
+            "GSTools: given variogram model is not a CovModel instance."
+        )
+    if GSTOOLS_VERSION < [1, 3]:
+        raise GSToolsException("GSTools: need at least GSTools v1.3.")
+    if model.latlon and GSTOOLS_VERSION < [1, 4]:
+        raise GSToolsException(
+            "GSTools: latlon models in PyKrige are only supported from GSTools v1.4."
+        )

src/pykrige/ok.py

@@ -28,6 +28,7 @@
 from scipy.spatial.distance import cdist
 
 from . import core, variogram_models
+from .compat_gstools import validate_gstools
 from .core import (
     P_INV,
     _adjust_for_anisotropy,
@@ -217,12 +218,20 @@ def __init__(
             raise ValueError("exact_values has to be boolean True or False")
         self.exact_values = exact_values
 
+        self.coordinates_type = coordinates_type
+
         # check if a GSTools covariance model is given
         if hasattr(self.variogram_model, "pykrige_kwargs"):
             # save the model in the class
             self.model = self.variogram_model
-            if self.model.dim == 3:
+            validate_gstools(self.model)
+            if self.model.field_dim == 3:
                 raise ValueError("GSTools: model dim is not 1 or 2")
+            # check if coordinate types match
+            if self.model.latlon and (self.coordinates_type == "euclidean"):
+                raise ValueError(
+                    "GSTools: latlon models require geographic coordinates"
+                )
             self.variogram_model = "custom"
             variogram_function = self.model.pykrige_vario
             variogram_parameters = []
@@ -265,7 +274,7 @@ def __init__(
 
         # adjust for anisotropy... only implemented for euclidean (rectangular)
         # coordinates, as anisotropy is ambiguous for geographic coordinates...
-        if coordinates_type == "euclidean":
+        if self.coordinates_type == "euclidean":
             self.XCENTER = (np.amax(self.X_ORIG) + np.amin(self.X_ORIG)) / 2.0
             self.YCENTER = (np.amax(self.Y_ORIG) + np.amin(self.Y_ORIG)) / 2.0
             self.anisotropy_scaling = anisotropy_scaling
@@ -278,7 +287,7 @@ def __init__(
                 [self.anisotropy_scaling],
                 [self.anisotropy_angle],
             ).T
-        elif coordinates_type == "geographic":
+        elif self.coordinates_type == "geographic":
             # Leave everything as is in geographic case.
             # May be open to discussion?
             if anisotropy_scaling != 1.0:
@@ -298,7 +307,6 @@ def __init__(
                 "Only 'euclidean' and 'geographic' are valid "
                 "values for coordinates-keyword."
             )
-        self.coordinates_type = coordinates_type
 
         if self.verbose:
             print("Initializing variogram model...")
@@ -422,8 +430,14 @@ def update_variogram_model(
         if hasattr(self.variogram_model, "pykrige_kwargs"):
             # save the model in the class
             self.model = self.variogram_model
-            if self.model.dim == 3:
+            validate_gstools(self.model)
+            if self.model.field_dim == 3:
                 raise ValueError("GSTools: model dim is not 1 or 2")
+            # check if coordinate types match
+            if self.model.latlon and (self.coordinates_type == "euclidean"):
+                raise ValueError(
+                    "GSTools: latlon models require geographic coordinates"
+                )
             self.variogram_model = "custom"
             variogram_function = self.model.pykrige_vario
             variogram_parameters = []

src/pykrige/ok3d.py

@@ -27,6 +27,7 @@
 from scipy.spatial.distance import cdist
 
 from . import core, variogram_models
+from .compat_gstools import validate_gstools
 from .core import (
     P_INV,
     _adjust_for_anisotropy,
@@ -234,7 +235,8 @@ def __init__(
         if hasattr(self.variogram_model, "pykrige_kwargs"):
             # save the model in the class
             self.model = self.variogram_model
-            if self.model.dim < 3:
+            validate_gstools(self.model)
+            if self.model.field_dim < 3:
                 raise ValueError("GSTools: model dim is not 3")
             self.variogram_model = "custom"
             variogram_function = self.model.pykrige_vario
@@ -430,7 +432,8 @@ def update_variogram_model(
         if hasattr(self.variogram_model, "pykrige_kwargs"):
             # save the model in the class
             self.model = self.variogram_model
-            if self.model.dim < 3:
+            validate_gstools(self.model)
+            if self.model.field_dim < 3:
                 raise ValueError("GSTools: model dim is not 3")
             self.variogram_model = "custom"
             variogram_function = self.model.pykrige_vario

src/pykrige/uk.py

@@ -26,6 +26,7 @@
 from scipy.spatial.distance import cdist
 
 from . import core, variogram_models
+from .compat_gstools import validate_gstools
 from .core import (
     P_INV,
     _adjust_for_anisotropy,
@@ -267,8 +268,13 @@ def __init__(
         if hasattr(self.variogram_model, "pykrige_kwargs"):
             # save the model in the class
             self.model = self.variogram_model
-            if self.model.dim == 3:
+            validate_gstools(self.model)
+            if self.model.field_dim == 3:
                 raise ValueError("GSTools: model dim is not 1 or 2")
+            if self.model.latlon:
+                raise ValueError(
+                    "GSTools: latlon models not supported for universal kriging"
+                )
             self.variogram_model = "custom"
             variogram_function = self.model.pykrige_vario
             variogram_parameters = []
@@ -673,8 +679,13 @@ def update_variogram_model(
         if hasattr(self.variogram_model, "pykrige_kwargs"):
             # save the model in the class
             self.model = self.variogram_model
-            if self.model.dim == 3:
+            validate_gstools(self.model)
+            if self.model.field_dim == 3:
                 raise ValueError("GSTools: model dim is not 1 or 2")
+            if self.model.latlon:
+                raise ValueError(
+                    "GSTools: latlon models not supported for universal kriging"
+                )
             self.variogram_model = "custom"
             variogram_function = self.model.pykrige_vario
             variogram_parameters = []

src/pykrige/uk3d.py

@@ -26,6 +26,7 @@
 from scipy.spatial.distance import cdist
 
 from . import core, variogram_models
+from .compat_gstools import validate_gstools
 from .core import (
     P_INV,
     _adjust_for_anisotropy,
@@ -262,7 +263,8 @@ def __init__(
         if hasattr(self.variogram_model, "pykrige_kwargs"):
             # save the model in the class
             self.model = self.variogram_model
-            if self.model.dim < 3:
+            validate_gstools(self.model)
+            if self.model.field_dim < 3:
                 raise ValueError("GSTools: model dim is not 3")
             self.variogram_model = "custom"
             variogram_function = self.model.pykrige_vario
@@ -515,7 +517,8 @@ def update_variogram_model(
         if hasattr(self.variogram_model, "pykrige_kwargs"):
             # save the model in the class
             self.model = self.variogram_model
-            if self.model.dim < 3:
+            validate_gstools(self.model)
+            if self.model.field_dim < 3:
                 raise ValueError("GSTools: model dim is not 3")
             self.variogram_model = "custom"
             variogram_function = self.model.pykrige_vario