Revert back some inversion checks from pr #1089 and small bugfix in i…

…tslive (#1094)

* New attempt

* pep8

oggm/core/centerlines.py

@@ -284,8 +284,8 @@ def set_apparent_mb(self, mb, mu_star=None):
         flux_needs_correction = False
         flux = np.cumsum(self.flux + mb * self.widths * self.dx)
 
-        # We filter only lines with two negative grid points, the
-        # rest we can cope with
+        # We filter only lines with two negative grid points,
+        # the rest we can cope with
         if flux[-2] < 0:
             flux_needs_correction = True
 

oggm/core/climate.py

@@ -998,6 +998,27 @@ def local_t_star(gdir, *, ref_df=None, tstar=None, bias=None):
     gdir.write_json(df, 'local_mustar')
 
 
+def _check_terminus_mass_flux(gdir, fls, cmb):
+    # Avoid code duplication
+
+    rho = cfg.PARAMS['ice_density']
+
+    # This variable is in "sensible" units normalized by width
+    flux = fls[-1].flux[-1]
+    aflux = flux * (gdir.grid.dx ** 2) / rho  # m3 ice per year
+
+    # If not marine and a bit far from zero, warning
+    if cmb == 0 and flux > 0 and not np.allclose(flux, 0, atol=0.01):
+        log.info('(%s) flux should be zero, but is: '
+                 '%.4f m3 ice yr-1', gdir.rgi_id, aflux)
+
+    # If not marine and quite far from zero, error
+    if cmb == 0 and flux > 0 and not np.allclose(flux, 0, atol=1):
+        msg = ('({}) flux should be zero, but is: {:.4f} m3 ice yr-1'
+               .format(gdir.rgi_id, aflux))
+        raise MassBalanceCalibrationError(msg)
+
+
 def _mu_star_per_minimization(x, fls, cmb, temp, prcp, widths):
 
     # Get the corresponding mu

oggm/core/inversion.py

@@ -93,7 +93,7 @@ def prepare_for_inversion(gdir, add_debug_var=False,
             log.info('(%s) has negative flux somewhere', gdir.rgi_id)
         utils.clip_min(flux, 0, out=flux)
 
-        if np.sum(flux <= 0) > 1:
+        if np.sum(flux <= 0) > 1 and len(fls) == 1:
             raise RuntimeError("More than one grid point has zero or "
                                "negative flux: this should not happen.")
 

oggm/params.cfg

@@ -213,7 +213,7 @@ max_mu_star = 10000.
 clip_mu_star = False
 # For some glacier geometries, having one mu* for the entire glacier implies
 # that some tributaries should not exist and have a negative mass flux
-# somewhere along their flowline.
+# at the terminus of their flowline.
 # This problem can be solved by computing a different mu* for these
 # tributaries (recommended)
 correct_for_neg_flux = True

oggm/shop/its_live.py

@@ -164,7 +164,7 @@ def _reproject_and_scale(gdir, do_error=False):
         if do_error:
             ln = 'Uncertainty of ' + ln
         v.long_name = ln
-        v[:] = vx
+        v[:] = vx.filled(np.nan)
 
         vn = 'obs_icevel_y'
         if do_error:
@@ -178,7 +178,7 @@ def _reproject_and_scale(gdir, do_error=False):
         if do_error:
             ln = 'Uncertainty of ' + ln
         v.long_name = ln
-        v[:] = vy
+        v[:] = vy.filled(np.nan)
 
 
 @utils.entity_task(log, writes=['gridded_data'])