make advection interface more readable

pyro/advection/interface.py

@@ -7,9 +7,6 @@ def linear_interface(a, myg, rp, dt):
     u = rp.get_param("advection.u")
     v = rp.get_param("advection.v")
 
-    cx = u*dt/myg.dx
-    cy = v*dt/myg.dy
-
     # --------------------------------------------------------------------------
     # monotonized central differences
     # --------------------------------------------------------------------------
@@ -27,30 +24,26 @@ def linear_interface(a, myg, rp, dt):
 
     # upwind
     if u < 0:
-        # a_x[i,j] = a[i,j] - 0.5*(1.0 + cx)*ldelta_a[i,j]
-        # a_x.v(buf=1)[:, :] = a.v(buf=1) - 0.5*(1.0 + cx)*ldelta_ax.v(buf=1)
-        a_x.v(buf=1)[:, :] = a.v(buf=1) - 0.5*myg.dx*ldelta_ax.v(buf=1) \
-                                        - 0.5*dt*ldelta_Fx.v(buf=1)
+        # a_x[i,j] = a[i,j] - 0.5*ldelta_ax[i,j] - 0.5*dt/dx*ldelta_Fx[i,j]
+        a_x.v(buf=1)[:, :] = a.v(buf=1) - 0.5*ldelta_ax.v(buf=1) \
+                                        - 0.5*dt/myg.dx*ldelta_Fx.v(buf=1)
 
     else:
-        # a_x[i,j] = a[i-1,j] + 0.5*(1.0 - cx)*ldelta_a[i-1,j]
-        # a_x.v(buf=1)[:, :] = a.ip(-1, buf=1) + 0.5*(1.0 - cx)*ldelta_ax.ip(-1, buf=1)
-        a_x.v(buf=1)[:, :] = a.v(buf=1) + 0.5*myg.dy*ldelta_ax.ip(-1, buf=1)
-                                        - 0.5*dt*ldelta_Fx.ip(-1, buf=1)
+        # a_x[i,j] = a[i-1,j] + 0.5*ldelta_ax[i-1,j] - 0.5*dt/dx*ldelta_Fx[i-1,j]
+        a_x.v(buf=1)[:, :] = a.ip(-1, buf=1) + 0.5*ldelta_ax.ip(-1, buf=1) \
+                                             - 0.5*dt/myg.dx*ldelta_Fx.ip(-1, buf=1)
 
     # y-direction
     a_y = myg.scratch_array()
 
     # upwind
     if v < 0:
-        # a_y[i,j] = a[i,j] - 0.5*(1.0 + cy)*ldelta_a[i,j]
-        # a_y.v(buf=1)[:, :] = a.v(buf=1) - 0.5*(1.0 + cy)*ldelta_ay.v(buf=1)
-        a_y.v(buf=1)[:, :] = a.v(buf=1) - 0.5*myg.dy*ldelta_ay.v(buf=1) \
-                                        - 0.5*dt*ldelta_Fy.v(buf=1)
+        # a_y[i,j] = a[i,j] - 0.5*ldelta_ay[i,j] - 0.5*dt/dy*ldelta_Fy[i,j]
+        a_y.v(buf=1)[:, :] = a.v(buf=1) - 0.5*ldelta_ay.v(buf=1) \
+                                        - 0.5*dt/myg.dy*ldelta_Fy.v(buf=1)
     else:
-        # a_y[i,j] = a[i,j-1] + 0.5*(1.0 - cy)*ldelta_a[i,j-1]
-        # a_y.v(buf=1)[:, :] = a.jp(-1, buf=1) + 0.5*(1.0 - cy)*ldelta_ay.jp(-1, buf=1)
-        a_y.v(buf=1)[:, :] = a.v(buf=1) - 0.5*myg.dy*ldelta_ay.jp(-1, buf=1) \
-                                        - 0.5*dt*ldelta_Fy.jp(-1, buf=1)
+        # a_y[i,j] = a[i,j-1] + 0.5*ldelta_ay[i,j-1] - 0.5*dt/dy*ldelta_Fy[i,j-1]
+        a_y.v(buf=1)[:, :] = a.jp(-1, buf=1) + 0.5*ldelta_ay.jp(-1, buf=1) \
+                                        - 0.5*dt/myg.dy*ldelta_Fy.jp(-1, buf=1)
 
     return u, v, a_x, a_y

pyro/mesh/patch.py

@@ -234,7 +234,7 @@ def A_y(self, j=0, buf=0):
 
     def V(self, i=0, j=0, buf=0):
         """
-        Returns the area
+        Returns the volume
         parameter:
         -----------
         i : shifts the array in the x-direction by index i
@@ -245,6 +245,7 @@ def V(self, i=0, j=0, buf=0):
         return self.vol[self.ilo+i+buf:self.ihi+1+i+buf,
                         self.jlo+j+buf:self.jhi+1+j+buf]
 
+
 class SphericalPolar(Grid2d):
     """
     This class defines a spherical polar grid.
@@ -311,7 +312,7 @@ def A_y(self, j=0, buf=0):
 
     def V(self, i=0, j=0, buf=0):
         """
-        Returns the area
+        Returns the volume
         parameter:
         -----------
         i : shifts the array in the x-direction by index i
@@ -323,8 +324,6 @@ def V(self, i=0, j=0, buf=0):
                         self.jlo+j+buf:self.jhi+1+j+buf]
 
 
-
-
 class CellCenterData2d:
     """
     A class to define cell-centered data that lives on a grid.  A