Added a writeField API.

Author: friedenhe

pyofm/pyOFM.py

@@ -320,3 +320,18 @@ def readField(self, fieldName, fieldType, timeName, field):
         """
 
         self.ofMesh.readField(fieldName, fieldType, timeName, field)
+    
+    def writeField(self, fieldName, fieldType, field):
+        """
+        Write OpenFoam field based on the internal field values from an array
+
+        Inputs:
+            fieldName: name of the field to read
+            fieldType: can be either volScalarField or volVectorField
+            field: an np array to save values of the field
+        Output:
+            An OpenFOAM field variable written to the disk (usually in the 0 folder)
+            
+        """
+
+        self.ofMesh.writeField(fieldName, fieldType, field)

src/OFMesh.H

@@ -223,6 +223,65 @@ public:
                                       << " not supported! Options are volScalariField or volVectorField" << abort(FatalError);
         }
     }
+
+    void writeField(
+        const word fieldName,
+        const word fieldType,
+        const double* field)
+    {
+        if (fieldType == "volScalarField")
+        {
+            volScalarField state(
+                IOobject(
+                    fieldName,
+                    "0",
+                    meshPtr_(),
+                    IOobject::NO_READ,
+                    IOobject::NO_WRITE,
+                    false),
+                meshPtr_(),
+                dimensionedScalar(fieldName, dimensionSet(0, 0, 0, 0, 0, 0, 0), 0.0),
+                "zeroGradient");
+
+            forAll(state, cellI)
+            {
+                state[cellI] = field[cellI];
+            }
+            state.correctBoundaryConditions();
+            state.write();
+        }
+        else if (fieldType == "volVectorField")
+        {
+            volVectorField state(
+                IOobject(
+                    fieldName,
+                    "0",
+                    meshPtr_(),
+                    IOobject::NO_READ,
+                    IOobject::NO_WRITE,
+                    false),
+                meshPtr_(),
+                dimensionedVector(fieldName, dimensionSet(0, 0, 0, 0, 0, 0, 0), vector::zero),
+                "zeroGradient");
+
+            label counterI = 0;
+            forAll(state, cellI)
+            {
+                for (label i = 0; i < 3; i++)
+                {
+                    state[cellI][i] = field[counterI];
+                    counterI++;
+                }
+            }
+            state.correctBoundaryConditions();
+            state.write();
+        }
+        else
+        {
+            FatalErrorIn("readField") << "fieldType " << fieldType
+                                      << " not supported! Options are volScalariField or volVectorField" << abort(FatalError);
+        }
+    }
 };
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

src/pyOFMesh.pyx

@@ -42,6 +42,7 @@ cdef extern from "OFMesh.H" namespace "Foam":
         int getLocalBoundaryFaceOwner(int,int)
         int getLocalFaceNeighbour(int)
         void readField(char* , char *, char *, double *)
+        void writeField(char* , char *, double *)
 
 # create python wrappers that call cpp functions
 cdef class pyOFMesh:
@@ -146,3 +147,15 @@ cdef class pyOFMesh:
 
         cdef double *field_data = <double*>field.data
         self._thisptr.readField(fieldName.encode(), fieldType.encode(), timeName.encode(), field_data)
+    
+    def writeField(self, fieldName, fieldType, np.ndarray[double, ndim=1, mode="c"] field):
+        if fieldType == "volScalarField":
+            assert len(field) == self.getNLocalCells(), "invalid array size!"
+        elif fieldType == "volVectorField":
+            assert len(field) == self.getNLocalCells() * 3, "invalid array size!"
+        else:
+            print("fieldType invalid!")
+            exit(1)
+        
+        cdef double *field_data = <double*>field.data
+        self._thisptr.writeField(fieldName.encode(), fieldType.encode(), field_data)