Catch errors in HypnotoadGui.run()

doc/whats-new.md

@@ -2,6 +2,16 @@ What's new
 ==========
 
 
+0.1.1 (unreleased)
+------------------
+
+### New Features
+
+- Catch errors in HypnotoadGui.run(), allows changing settings and pressing Run
+  button again if there was an error in grid generation (#24)\
+  By [John Omotani](https://github.com/johnomotani)
+
+
 0.1.0 (24th April 2020)
 -----------------------
 

hypnotoad/cases/tokamak.py

@@ -68,6 +68,11 @@ class TokamakEquilibrium(Equilibrium):
         psi_sol_inner=None,  # Default: psinorm_sol_inner
         psi_pf_lower=None,  # Default: psinorm_pf_lower
         psi_pf_upper=None,  # Default: psinorm_pf_upper
+        #
+        # Tolerance for positioning points that should be at X-point, but need to be
+        # slightly displaced from the null so code can follow Grad(psi).
+        # Number between 0. and 1.
+        xpoint_offset=0.5,
     ).push(
         Options(
             # These are HypnotoadOptions
@@ -236,6 +241,9 @@ class Options (self.user_options)
 
         super().__init__(**kwargs)
 
+        # Print the table of options
+        print(optionsTableString(self.user_options, self.default_options))
+
         if make_regions:
             # Create self.regions
             self.makeRegions()
@@ -470,9 +478,6 @@ def psi_to_psinorm(psi):
             np.abs((self.user_options.psi_core - self.user_options.psi_sol) / 20.0),
         )
 
-        # Print the table of options
-        print(optionsTableString(self.user_options, self.default_options))
-
         # Filter out the X-points not in range.
         # Keep only those with normalised psi < psinorm_sol
         self.psi_sep, self.x_points = zip(
@@ -1179,7 +1184,9 @@ def psival(angle):
             ]
 
             # Add points to the beginning and end near (but not at) the X-points
-            diff = 0.5
+            diff = self.user_options.xpoint_offset
+            if diff < 0.0 or diff > 1.0:
+                raise ValueError(f"xpoint_offset={diff} should be between 0 and 1.")
 
             region["points"] = (
                 [(1.0 - diff) * start_x + diff * points[0]]

hypnotoad/gui/gui.py

@@ -22,6 +22,7 @@
 from .matplotlib_widget import MatplotlibWidget
 from ..cases import tokamak
 from ..core.mesh import BoutMesh
+from ..core.equilibrium import SolutionError
 from ..__init__ import __version__
 
 
@@ -323,8 +324,22 @@ def run(self):
             )
             return
 
+        # Call read_geqdsk to recreate self.eq object in case any settings needed in
+        # __init__ have been changed
+        self.read_geqdsk()
+
         self.statusbar.showMessage("Running...")
-        self.mesh = BoutMesh(self.eq)
+        try:
+            self.mesh = BoutMesh(self.eq)
+        except (ValueError, SolutionError):
+            self.statusbar.showMessage(
+                "Error in grid generation, change settings and run again!"
+            )
+            self.statusbar.setStyleSheet(
+                f"QLineEdit {{ background-color: {COLOURS['red']} }}"
+            )
+            return
+
         self.mesh.calculateRZ()
         self.statusbar.showMessage("Done!", 2000)