Taup fix for models with no discontinuities

CHANGELOG.txt

@@ -17,6 +17,9 @@ Changes:
  - obspy.io.gcf:
    * Fixed an issue in algorithm to split and encode last few data into GCF 
      blocks (see #3252)
+ - obspy.taup:
+   * bugfix to allow calculations for a model with no discontinuities
+     (see #3070, #3244)
 
 1.4.0 (doi: 10.5281/zenodo.6645832)
 ===================================

obspy/taup/taup_create.py

@@ -124,7 +124,7 @@ def run(self):
                 os.makedirs(dirname)
             self.tau_model.serialize(self.output_filename)
             if self.debug:
-                print("Done Saving " + self.output_filename)
+                print("Done Saving " + str(self.output_filename))
         except IOError as e:
             print("Tried to write!\n Caught IOError. Do you have write "
                   "permission in this directory?", e)

obspy/taup/tests/test_tau.py

@@ -1034,14 +1034,12 @@ def test_arrivals_class(self):
     def test_regional_models(self, testdata):
         """
         Tests small regional models as this used to not work.
-
-        Note: It looks like too much work to get a 1-layer model working.
-        The problem is first in finding the moho, and second in coarsely-
-        sampling slowness. Also, why bother.
         """
-        model_names = ["2_layer_model", "5_layer_model",
+        model_names = ["1_layer_model", "2_layer_model", "5_layer_model",
                        "2_layer_no_discontinuity_model"]
         expected_results = [
+            [("p", 18.143), ("sP", 22.054), ("s", 31.509), ("PP", 4107.380),
+             ("SP", 5619.257), ("PS", 5621.396), ("SS", 7133.265)],
             [("p", 18.143), ("P", 19.202), ("Pn", 19.202), ("P", 19.884),
              ("sP", 22.054), ("pP", 23.023), ("pP", 23.038), ("sP", 25.656),
              ("sP", 25.759), ("s", 31.509), ("S", 33.395), ("Sn", 33.395),

obspy/taup/velocity_model.py

@@ -629,6 +629,13 @@ def fix_discontinuity_depths(self):
             above['bot_p_velocity'] != below['top_p_velocity'],
             above['bot_s_velocity'] != below['top_s_velocity'])
 
+        if len(mask) == 0:
+            # Special case where have no discontinuities
+            self.moho_depth = temp_moho_depth
+            self.cmb_depth = temp_cmb_depth
+            self.iocb_depth = temp_iocb_depth
+            return
+
         # Find discontinuity closest to current Moho
         moho_diff = np.abs(self.moho_depth - above['bot_depth'])
         moho_diff[~mask] = moho_min