Also write data at intermediate time steps.

partitioned-heat-conduction/fenics/heat.py

@@ -157,13 +157,25 @@ def determine_gradient(V_g, u, flux):
 
 # output solution and reference solution at t=0, n=0
 n = 0
-print('output u^%d and u_ref^%d' % (n, n))
-temperature_out << (u_n, t)
-ref_out << u_ref
+print("output u^%d and u_ref^%d" % (n, n))
 ranks << mesh_rank
 
 error_total, error_pointwise = compute_errors(u_n, u_ref, V)
-error_out << error_pointwise
+
+# create buffer for output. We need this buffer, because we only want to write the converged output at the end of the window, but we also want to write the samples that are resulting from substeps inside the window
+u_write = []
+ref_write = []
+error_write = []
+# copy data to buffer and rename
+uu = u_n.copy()
+uu.rename("u","")
+u_write.append((uu, t))
+uu_ref = u_ref.copy()
+uu_ref.rename("u_ref","")
+ref_write.append(uu_ref)
+err = error_pointwise.copy()
+err.rename("err","")
+error_write.append(err)
 
 # set t_1 = t_0 + dt, this gives u_D^1
 # call dt(0) to evaluate FEniCS Constant. Todo: is there a better way?
@@ -180,6 +192,17 @@ def determine_gradient(V_g, u, flux):
     if precice.requires_writing_checkpoint():
         precice.store_checkpoint(u_n, t, n)
 
+        # output solution and reference solution at t_n+1 and substeps (read from buffer)
+        print('output u^%d and u_ref^%d' % (n, n))
+        for sample in u_write:
+            temperature_out << sample
+
+        for sample in ref_write:
+            ref_out << sample
+
+        for sample in error_write:
+            error_out << error_pointwise
+
     dt.assign(np.min([fenics_dt, precice_dt]))
     read_data = precice.read_data(dt)
 
@@ -208,25 +231,46 @@ def determine_gradient(V_g, u, flux):
         u_n.assign(u_cp)
         t = t_cp
         n = n_cp
+        # empty buffer if window has not converged
+        u_write = []
+        ref_write = []
+        error_write = []
     else:  # update solution
         u_n.assign(u_np1)
         t += float(dt)
         n += 1
+        # copy data to buffer and rename
+        uu = u_n.copy()
+        uu.rename("u","u")
+        u_write.append((uu, t))
+        uu_ref = u_ref.copy()
+        uu_ref.rename("u_ref","u_ref")
+        ref_write.append(uu_ref)
+        err = error_pointwise.copy()
+        err.rename("err","err")
+        error_write.append(err)
 
     if precice.is_time_window_complete():
         u_ref = interpolate(u_D, V)
         u_ref.rename("reference", " ")
         error, error_pointwise = compute_errors(u_n, u_ref, V, total_error_tol=error_tol)
-        print('n = %d, t = %.2f: L2 error on domain = %.3g' % (n, t, error))
-        # output solution and reference solution at t_n+1
-        print('output u^%d and u_ref^%d' % (n, n))
-        temperature_out << (u_n, t)
-        ref_out << u_ref
-        error_out << error_pointwise
+        print("n = %d, t = %.2f: L2 error on domain = %.3g" % (n, t, error))
+
 
     # Update Dirichlet BC
     u_D.t = t + float(dt)
     f.t = t + float(dt)
 
+# output solution and reference solution at t_n+1 and substeps (read from buffer)
+print("output u^%d and u_ref^%d" % (n, n))
+for sample in u_write:
+    temperature_out << sample
+
+for sample in ref_write:
+    ref_out << sample
+
+for sample in error_write:
+    error_out << error_pointwise
+
 # Hold plot
 precice.finalize()