support for wellpathpy for minimum curvature desurvey

geoh5py/objects/drillhole.py

@@ -456,9 +456,42 @@ def desurvey(self, depths):
         if isinstance(depths, list):
             depths = np.asarray(depths)
 
+        surveys = self.surveys.copy()
+
         # Repeat first survey point at surface for de-survey interpolation
-        surveys = np.vstack([self.surveys[0, :], self.surveys])
-        surveys[0, 0] = 0.0
+        # (only if needed)
+        if surveys[0, 0] != 0.0:
+            surveys = np.vstack([surveys[0, :], surveys])
+            surveys[0, 0] = 0.0
+
+        try:
+            import wellpathpy as wp
+
+            # Repeat last survey point at bottom depth of desurvey request
+            # TODO there is a mathematically more correct way to do this.
+            if surveys[-1, 0] < depths[-1]:
+                surveys = np.vstack([surveys, surveys[-1, :]])
+                surveys[-1, 0] = depths[-1]
+
+            # geoh5py dips range from -90 to 0
+            # wellpathpy expects inclination inc | 0 <= inc < 180
+            # where 180 = 90 degree dip (vertical), so never truly vertical?
+            surveys[:, 2] = surveys[:, 2] + 90.00000000001
+
+            dev = wp.deviation(md=surveys[:, 0], azi=surveys[:, 1], inc=surveys[:, 2])
+            pos = dev.minimum_curvature().resample(depths)
+
+            return np.c_[
+                [
+                    self.locations[0, 0] + pos.easting,
+                    self.locations[0, 1] + pos.northing,
+                    self.locations[0, 2] - pos.depth,
+                ]
+            ].T
+        except Exception as e:
+            print("cannot do wellpathpy")
+            print(e)
+
 
         ind_loc = np.maximum(
             np.searchsorted(surveys[:, 0], depths, side="left") - 1,