xref: /petsc/src/sys/classes/viewer/impls/matlab/vmatlab.c (revision 811af0c4b09a35de4306c442f88bd09fdc09897d)
15c6c1daeSBarry Smith 
2af0996ceSBarry Smith #include <petsc/private/viewerimpl.h>
35c6c1daeSBarry Smith #include <mat.h>
45c6c1daeSBarry Smith 
55c6c1daeSBarry Smith typedef struct {
65c6c1daeSBarry Smith   MATFile      *ep;
75c6c1daeSBarry Smith   PetscMPIInt   rank;
85c6c1daeSBarry Smith   PetscFileMode btype;
95c6c1daeSBarry Smith } PetscViewer_Matlab;
105c6c1daeSBarry Smith 
115c6c1daeSBarry Smith /*@C
12*811af0c4SBarry Smith     PetscViewerMatlabPutArray - Puts an array into the `PETSCVIEWERMATLAB` viewer.
135c6c1daeSBarry Smith 
145c6c1daeSBarry Smith       Not collective: only processor zero saves the array
155c6c1daeSBarry Smith 
165c6c1daeSBarry Smith     Input Parameters:
175c6c1daeSBarry Smith +    mfile - the viewer
185c6c1daeSBarry Smith .    m,n - the dimensions of the array
195c6c1daeSBarry Smith .    array - the array (represented in one dimension)
205c6c1daeSBarry Smith -    name - the name of the array
215c6c1daeSBarry Smith 
225c6c1daeSBarry Smith    Level: advanced
235c6c1daeSBarry Smith 
24*811af0c4SBarry Smith     Note:
2595452b02SPatrick Sanan     Only writes array values on processor 0.
265c6c1daeSBarry Smith 
27*811af0c4SBarry Smith .seealso: `PETSCVIEWERMATLAB`, `PetscViewerMatlabGetArray()`
285c6c1daeSBarry Smith @*/
299371c9d4SSatish Balay PetscErrorCode PetscViewerMatlabPutArray(PetscViewer mfile, int m, int n, const PetscScalar *array, const char *name) {
302cb5e1ccSBarry Smith   PetscViewer_Matlab *ml;
315c6c1daeSBarry Smith   mxArray            *mat;
325c6c1daeSBarry Smith 
335c6c1daeSBarry Smith   PetscFunctionBegin;
3428b400f6SJacob Faibussowitsch   PetscCheck(mfile, PETSC_COMM_SELF, PETSC_ERR_ARG_NULL, "Null argument: probably PETSC_VIEWER_MATLAB_() failed");
352cb5e1ccSBarry Smith   ml = (PetscViewer_Matlab *)mfile->data;
365c6c1daeSBarry Smith   if (!ml->rank) {
379566063dSJacob Faibussowitsch     PetscCall(PetscInfo(mfile, "Putting MATLAB array %s\n", name));
385c6c1daeSBarry Smith #if !defined(PETSC_USE_COMPLEX)
395c6c1daeSBarry Smith     mat = mxCreateDoubleMatrix(m, n, mxREAL);
405c6c1daeSBarry Smith #else
415c6c1daeSBarry Smith     mat = mxCreateDoubleMatrix(m, n, mxCOMPLEX);
425c6c1daeSBarry Smith #endif
439566063dSJacob Faibussowitsch     PetscCall(PetscArraycpy(mxGetPr(mat), array, m * n));
445c6c1daeSBarry Smith     matPutVariable(ml->ep, name, mat);
455c6c1daeSBarry Smith 
469566063dSJacob Faibussowitsch     PetscCall(PetscInfo(mfile, "Put MATLAB array %s\n", name));
475c6c1daeSBarry Smith   }
485c6c1daeSBarry Smith   PetscFunctionReturn(0);
495c6c1daeSBarry Smith }
505c6c1daeSBarry Smith 
519371c9d4SSatish Balay PetscErrorCode PetscViewerMatlabPutVariable(PetscViewer viewer, const char *name, void *mat) {
52a297a907SKarl Rupp   PetscViewer_Matlab *ml = (PetscViewer_Matlab *)viewer->data;
535c6c1daeSBarry Smith 
545c6c1daeSBarry Smith   PetscFunctionBegin;
555c6c1daeSBarry Smith   matPutVariable(ml->ep, name, (mxArray *)mat);
565c6c1daeSBarry Smith   PetscFunctionReturn(0);
575c6c1daeSBarry Smith }
585c6c1daeSBarry Smith 
595c6c1daeSBarry Smith /*@C
60*811af0c4SBarry Smith     PetscViewerMatlabGetArray - Gets a variable from a `PETSCVIEWERMATLAB` viewer into an array
615c6c1daeSBarry Smith 
625c6c1daeSBarry Smith     Not Collective; only processor zero reads in the array
635c6c1daeSBarry Smith 
645c6c1daeSBarry Smith     Input Parameters:
655c6c1daeSBarry Smith +    mfile - the MATLAB file viewer
665c6c1daeSBarry Smith .    m,n - the dimensions of the array
675c6c1daeSBarry Smith .    array - the array (represented in one dimension)
685c6c1daeSBarry Smith -    name - the name of the array
695c6c1daeSBarry Smith 
705c6c1daeSBarry Smith    Level: advanced
715c6c1daeSBarry Smith 
72*811af0c4SBarry Smith     Note:
7395452b02SPatrick Sanan     Only reads in array values on processor 0.
745c6c1daeSBarry Smith 
75*811af0c4SBarry Smith .seealso: `PETSCVIEWERMATLAB`, `PetscViewerMatlabPutArray()`
765c6c1daeSBarry Smith @*/
779371c9d4SSatish Balay PetscErrorCode PetscViewerMatlabGetArray(PetscViewer mfile, int m, int n, PetscScalar *array, const char *name) {
782cb5e1ccSBarry Smith   PetscViewer_Matlab *ml;
795c6c1daeSBarry Smith   mxArray            *mat;
805c6c1daeSBarry Smith 
815c6c1daeSBarry Smith   PetscFunctionBegin;
8228b400f6SJacob Faibussowitsch   PetscCheck(mfile, PETSC_COMM_SELF, PETSC_ERR_ARG_NULL, "Null argument: probably PETSC_VIEWER_MATLAB_() failed");
832cb5e1ccSBarry Smith   ml = (PetscViewer_Matlab *)mfile->data;
845c6c1daeSBarry Smith   if (!ml->rank) {
859566063dSJacob Faibussowitsch     PetscCall(PetscInfo(mfile, "Getting MATLAB array %s\n", name));
865c6c1daeSBarry Smith     mat = matGetVariable(ml->ep, name);
8728b400f6SJacob Faibussowitsch     PetscCheck(mat, PETSC_COMM_SELF, PETSC_ERR_LIB, "Unable to get array %s from matlab", name);
889566063dSJacob Faibussowitsch     PetscCall(PetscArraycpy(array, mxGetPr(mat), m * n));
899566063dSJacob Faibussowitsch     PetscCall(PetscInfo(mfile, "Got MATLAB array %s\n", name));
905c6c1daeSBarry Smith   }
915c6c1daeSBarry Smith   PetscFunctionReturn(0);
925c6c1daeSBarry Smith }
935c6c1daeSBarry Smith 
949371c9d4SSatish Balay PetscErrorCode PetscViewerFileSetMode_Matlab(PetscViewer viewer, PetscFileMode type) {
955c6c1daeSBarry Smith   PetscViewer_Matlab *vmatlab = (PetscViewer_Matlab *)viewer->data;
965c6c1daeSBarry Smith 
975c6c1daeSBarry Smith   PetscFunctionBegin;
985c6c1daeSBarry Smith   vmatlab->btype = type;
995c6c1daeSBarry Smith   PetscFunctionReturn(0);
1005c6c1daeSBarry Smith }
1015c6c1daeSBarry Smith 
1025c6c1daeSBarry Smith /*
1035c6c1daeSBarry Smith         Actually opens the file
1045c6c1daeSBarry Smith */
1059371c9d4SSatish Balay PetscErrorCode PetscViewerFileSetName_Matlab(PetscViewer viewer, const char name[]) {
1065c6c1daeSBarry Smith   PetscViewer_Matlab *vmatlab = (PetscViewer_Matlab *)viewer->data;
1075c6c1daeSBarry Smith   PetscFileMode       type    = vmatlab->btype;
1085c6c1daeSBarry Smith 
1095c6c1daeSBarry Smith   PetscFunctionBegin;
110cc73adaaSBarry Smith   PetscCheck(type != (PetscFileMode)-1, PETSC_COMM_SELF, PETSC_ERR_ORDER, "Must call PetscViewerFileSetMode() before PetscViewerFileSetName()");
1115c6c1daeSBarry Smith   if (vmatlab->ep) matClose(vmatlab->ep);
1125c6c1daeSBarry Smith 
1135c6c1daeSBarry Smith   /* only first processor opens file */
1145c6c1daeSBarry Smith   if (!vmatlab->rank) {
115a297a907SKarl Rupp     if (type == FILE_MODE_READ) vmatlab->ep = matOpen(name, "r");
1167e4fd573SVaclav Hapla     else if (type == FILE_MODE_WRITE) vmatlab->ep = matOpen(name, "w");
117f7d195e4SLawrence Mitchell     else {
118f7d195e4SLawrence Mitchell       PetscCheck(type != FILE_MODE_UNDEFINED, PetscObjectComm((PetscObject)viewer), PETSC_ERR_ORDER, "Must call PetscViewerFileSetMode() before PetscViewerFileSetName()");
119f7d195e4SLawrence Mitchell       SETERRQ(PetscObjectComm((PetscObject)viewer), PETSC_ERR_SUP, "Unsupported file mode %s", PetscFileModes[type]);
120f7d195e4SLawrence Mitchell     }
1215c6c1daeSBarry Smith   }
1225c6c1daeSBarry Smith   PetscFunctionReturn(0);
1235c6c1daeSBarry Smith }
1245c6c1daeSBarry Smith 
1259371c9d4SSatish Balay PetscErrorCode PetscViewerDestroy_Matlab(PetscViewer v) {
1265c6c1daeSBarry Smith   PetscViewer_Matlab *vf = (PetscViewer_Matlab *)v->data;
1275c6c1daeSBarry Smith 
1285c6c1daeSBarry Smith   PetscFunctionBegin;
1295c6c1daeSBarry Smith   if (vf->ep) matClose(vf->ep);
1309566063dSJacob Faibussowitsch   PetscCall(PetscFree(vf));
1312e956fe4SStefano Zampini   PetscCall(PetscObjectComposeFunction((PetscObject)v, "PetscViewerFileSetName_C", NULL));
1322e956fe4SStefano Zampini   PetscCall(PetscObjectComposeFunction((PetscObject)v, "PetscViewerFileSetMode_C", NULL));
1335c6c1daeSBarry Smith   PetscFunctionReturn(0);
1345c6c1daeSBarry Smith }
1355c6c1daeSBarry Smith 
1368556b5ebSBarry Smith /*MC
1378556b5ebSBarry Smith    PETSCVIEWERMATLAB - A viewer that saves the variables into a MATLAB .mat file that may be read into MATLAB
1388556b5ebSBarry Smith        with load('filename').
1398556b5ebSBarry Smith 
1408556b5ebSBarry Smith    Level: intermediate
1418556b5ebSBarry Smith 
142*811af0c4SBarry Smith        Note: Currently can only save PETSc vectors to .mat files, not matrices (use the `PETSCVIEWERBINARY` and
1438556b5ebSBarry Smith              ${PETSC_DIR}/share/petsc/matlab/PetscBinaryRead.m to read matrices into MATLAB).
1448556b5ebSBarry Smith 
145*811af0c4SBarry Smith              For parallel vectors obtained with `DMCreateGlobalVector()` or `DMGetGlobalVector()` the vectors are saved to
146*811af0c4SBarry Smith              the .mat file in natural ordering. You can use DMView() to save the `DMDA` information to the .mat file
147*811af0c4SBarry Smith              the fields in the MATLAB loaded da variable give the array dimensions so you can reshape the `MATLAB`
1488556b5ebSBarry Smith              vector to the same multidimensional shape as it had in PETSc for plotting etc. For example,
1498556b5ebSBarry Smith 
1508556b5ebSBarry Smith $             In your PETSc C/C++ code (assuming a two dimensional DMDA with one degree of freedom per node)
1518556b5ebSBarry Smith $                PetscObjectSetName((PetscObject)x,"x");
1528556b5ebSBarry Smith $                VecView(x,PETSC_VIEWER_MATLAB_WORLD);
1538556b5ebSBarry Smith $                PetscObjectSetName((PetscObject)da,"da");
1548556b5ebSBarry Smith $                DMView(x,PETSC_VIEWER_MATLAB_WORLD);
1558556b5ebSBarry Smith $             Then from MATLAB
1568556b5ebSBarry Smith $                load('matlaboutput.mat')   % matlaboutput.mat is the default filename
1578556b5ebSBarry Smith $                xnew = zeros(da.n,da.m);
1588556b5ebSBarry Smith $                xnew(:) = x;    % reshape one dimensional vector back to two dimensions
1598556b5ebSBarry Smith 
1608556b5ebSBarry Smith               If you wish to put the same variable into the .mat file several times you need to give it a new
1618556b5ebSBarry Smith               name before each call to view.
1628556b5ebSBarry Smith 
163*811af0c4SBarry Smith               Use `PetscViewerMatlabPutArray()` to just put an array of doubles into the .mat file
1648556b5ebSBarry Smith 
165c2e3fba1SPatrick Sanan .seealso: `PETSC_VIEWER_MATLAB_()`, `PETSC_VIEWER_MATLAB_SELF`, `PETSC_VIEWER_MATLAB_WORLD`, `PetscViewerCreate()`,
166db781477SPatrick Sanan           `PetscViewerMatlabOpen()`, `VecView()`, `DMView()`, `PetscViewerMatlabPutArray()`, `PETSCVIEWERBINARY`, `PETSCVIEWERASCII`, `PETSCVIEWERDRAW`,
167*811af0c4SBarry Smith           `PETSC_VIEWER_STDOUT_()`, `PetscViewerFileSetName()`, `PetscViewerFileSetMode()`, `PetscViewerFormat`, `PetscMatlabEngine`
1688556b5ebSBarry Smith M*/
1699371c9d4SSatish Balay PETSC_EXTERN PetscErrorCode PetscViewerCreate_Matlab(PetscViewer viewer) {
1705c6c1daeSBarry Smith   PetscViewer_Matlab *e;
1715c6c1daeSBarry Smith 
1725c6c1daeSBarry Smith   PetscFunctionBegin;
1739566063dSJacob Faibussowitsch   PetscCall(PetscNewLog(viewer, &e));
1749566063dSJacob Faibussowitsch   PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)viewer), &e->rank));
1757e4fd573SVaclav Hapla   e->btype     = FILE_MODE_UNDEFINED;
1765c6c1daeSBarry Smith   viewer->data = (void *)e;
177a297a907SKarl Rupp 
1789566063dSJacob Faibussowitsch   PetscCall(PetscObjectComposeFunction((PetscObject)viewer, "PetscViewerFileSetName_C", PetscViewerFileSetName_Matlab));
1799566063dSJacob Faibussowitsch   PetscCall(PetscObjectComposeFunction((PetscObject)viewer, "PetscViewerFileSetMode_C", PetscViewerFileSetMode_Matlab));
180a297a907SKarl Rupp 
1815c6c1daeSBarry Smith   viewer->ops->destroy = PetscViewerDestroy_Matlab;
1825c6c1daeSBarry Smith   PetscFunctionReturn(0);
1835c6c1daeSBarry Smith }
1845c6c1daeSBarry Smith 
1855c6c1daeSBarry Smith /*@C
1865c6c1daeSBarry Smith    PetscViewerMatlabOpen - Opens a Matlab .mat file for output
1875c6c1daeSBarry Smith 
188d083f849SBarry Smith    Collective
1895c6c1daeSBarry Smith 
1905c6c1daeSBarry Smith    Input Parameters:
1915c6c1daeSBarry Smith +  comm - MPI communicator
1925c6c1daeSBarry Smith .  name - name of file
1935c6c1daeSBarry Smith -  type - type of file
194*811af0c4SBarry Smith $    `FILE_MODE_WRITE` - create new file for MATLAB output
195*811af0c4SBarry Smith $    `FILE_MODE_READ` - open existing file for MATLAB input
196*811af0c4SBarry Smith $    ``FILE_MODE_WRITE - open existing file for MATLAB output
1975c6c1daeSBarry Smith 
1985c6c1daeSBarry Smith    Output Parameter:
1995c6c1daeSBarry Smith .  binv - PetscViewer for MATLAB output to use with the specified file
2005c6c1daeSBarry Smith 
2015c6c1daeSBarry Smith    Level: beginner
2025c6c1daeSBarry Smith 
203*811af0c4SBarry Smith    Notes:
204*811af0c4SBarry Smith    This `PetscViewer` should be destroyed with `PetscViewerDestroy()`.
2055c6c1daeSBarry Smith 
2065c6c1daeSBarry Smith    For writing files it only opens the file on processor 0 in the communicator.
2075c6c1daeSBarry Smith 
208*811af0c4SBarry Smith    This only saves `Vec`s it cannot be used to save `Mat`s. We recommend using the `PETSCVIEWERBINARY` to save objects to be loaded into MATLAB
2095c6c1daeSBarry Smith    instead of this routine.
2105c6c1daeSBarry Smith 
211*811af0c4SBarry Smith .seealso: `PETSCVIEWERMATLAB`, `PetscViewerASCIIOpen()`, `PetscViewerPushFormat()`, `PetscViewerDestroy()`, `PETSCVIEWERBINARY`, `PetscViewerBinaryOpen()`
212db781477SPatrick Sanan           `VecView()`, `MatView()`, `VecLoad()`, `MatLoad()`
2135c6c1daeSBarry Smith @*/
2149371c9d4SSatish Balay PetscErrorCode PetscViewerMatlabOpen(MPI_Comm comm, const char name[], PetscFileMode type, PetscViewer *binv) {
2155c6c1daeSBarry Smith   PetscFunctionBegin;
2169566063dSJacob Faibussowitsch   PetscCall(PetscViewerCreate(comm, binv));
2179566063dSJacob Faibussowitsch   PetscCall(PetscViewerSetType(*binv, PETSCVIEWERMATLAB));
2189566063dSJacob Faibussowitsch   PetscCall(PetscViewerFileSetMode(*binv, type));
2199566063dSJacob Faibussowitsch   PetscCall(PetscViewerFileSetName(*binv, name));
2205c6c1daeSBarry Smith   PetscFunctionReturn(0);
2215c6c1daeSBarry Smith }
2225c6c1daeSBarry Smith 
2235c6c1daeSBarry Smith static PetscMPIInt Petsc_Viewer_Matlab_keyval = MPI_KEYVAL_INVALID;
2245c6c1daeSBarry Smith 
2255c6c1daeSBarry Smith /*@C
226*811af0c4SBarry Smith      PETSC_VIEWER_MATLAB_ - Creates a `PETSCVIEWERMATLAB` `PetscViewer` shared by all processors
2275c6c1daeSBarry Smith                      in a communicator.
2285c6c1daeSBarry Smith 
229d083f849SBarry Smith      Collective
2305c6c1daeSBarry Smith 
2315c6c1daeSBarry Smith      Input Parameter:
232*811af0c4SBarry Smith .    comm - the MPI communicator to share the Matlab `PetscViewer`
233*811af0c4SBarry Smith 
234*811af0c4SBarry Smith    Options Database Key:
235*811af0c4SBarry Smith .    -viewer_matlab_filename <name> - name of the Matlab file
236*811af0c4SBarry Smith 
237*811af0c4SBarry Smith    Environmental variable:
238*811af0c4SBarry Smith .   `PETSC_VIEWER_MATLAB_FILENAME` - name of the Matlab file
2395c6c1daeSBarry Smith 
2405c6c1daeSBarry Smith      Level: intermediate
2415c6c1daeSBarry Smith 
242*811af0c4SBarry Smith      Note:
243*811af0c4SBarry Smith      Unlike almost all other PETSc routines, `PETSC_VIEWER_MATLAB_()` does not return
2445c6c1daeSBarry Smith      an error code.  The matlab PetscViewer is usually used in the form
2455c6c1daeSBarry Smith $       XXXView(XXX object,PETSC_VIEWER_MATLAB_(comm));
2465c6c1daeSBarry Smith 
247*811af0c4SBarry Smith      Use `PETSC_VIEWER_SOCKET_()` or `PetscViewerSocketOpen()` to communicator with an interactive MATLAB session.
2485c6c1daeSBarry Smith 
249db781477SPatrick Sanan .seealso: `PETSC_VIEWER_MATLAB_WORLD`, `PETSC_VIEWER_MATLAB_SELF`, `PetscViewerMatlabOpen()`, `PetscViewerCreate()`,
250db781477SPatrick Sanan           `PetscViewerDestroy()`
2515c6c1daeSBarry Smith @*/
2529371c9d4SSatish Balay PetscViewer PETSC_VIEWER_MATLAB_(MPI_Comm comm) {
2535c6c1daeSBarry Smith   PetscErrorCode ierr;
2545c6c1daeSBarry Smith   PetscBool      flg;
2555c6c1daeSBarry Smith   PetscViewer    viewer;
2565c6c1daeSBarry Smith   char           fname[PETSC_MAX_PATH_LEN];
2575c6c1daeSBarry Smith   MPI_Comm       ncomm;
2585c6c1daeSBarry Smith 
2595c6c1daeSBarry Smith   PetscFunctionBegin;
2609371c9d4SSatish Balay   ierr = PetscCommDuplicate(comm, &ncomm, NULL);
2619371c9d4SSatish Balay   if (ierr) {
2629371c9d4SSatish Balay     PetscError(PETSC_COMM_SELF, __LINE__, "PETSC_VIEWER_MATLAB_", __FILE__, PETSC_ERR_PLIB, PETSC_ERROR_INITIAL, " ");
2639371c9d4SSatish Balay     PetscFunctionReturn(0);
2649371c9d4SSatish Balay   }
2655c6c1daeSBarry Smith   if (Petsc_Viewer_Matlab_keyval == MPI_KEYVAL_INVALID) {
26612801b39SBarry Smith     ierr = MPI_Comm_create_keyval(MPI_COMM_NULL_COPY_FN, MPI_COMM_NULL_DELETE_FN, &Petsc_Viewer_Matlab_keyval, 0);
2679371c9d4SSatish Balay     if (ierr) {
2689371c9d4SSatish Balay       PetscError(PETSC_COMM_SELF, __LINE__, "PETSC_VIEWER_MATLAB_", __FILE__, PETSC_ERR_PLIB, PETSC_ERROR_INITIAL, " ");
2699371c9d4SSatish Balay       PetscFunctionReturn(NULL);
2709371c9d4SSatish Balay     }
2715c6c1daeSBarry Smith   }
27247435625SJed Brown   ierr = MPI_Comm_get_attr(ncomm, Petsc_Viewer_Matlab_keyval, (void **)&viewer, (int *)&flg);
2739371c9d4SSatish Balay   if (ierr) {
2749371c9d4SSatish Balay     PetscError(PETSC_COMM_SELF, __LINE__, "PETSC_VIEWER_MATLAB_", __FILE__, PETSC_ERR_PLIB, PETSC_ERROR_INITIAL, " ");
2759371c9d4SSatish Balay     PetscFunctionReturn(NULL);
2769371c9d4SSatish Balay   }
2775c6c1daeSBarry Smith   if (!flg) { /* PetscViewer not yet created */
2785c6c1daeSBarry Smith     ierr = PetscOptionsGetenv(ncomm, "PETSC_VIEWER_MATLAB_FILENAME", fname, PETSC_MAX_PATH_LEN, &flg);
2799371c9d4SSatish Balay     if (ierr) {
2809371c9d4SSatish Balay       PetscError(PETSC_COMM_SELF, __LINE__, "PETSC_VIEWER_MATLAB_", __FILE__, PETSC_ERR_PLIB, PETSC_ERROR_REPEAT, " ");
2819371c9d4SSatish Balay       PetscFunctionReturn(NULL);
2829371c9d4SSatish Balay     }
2835c6c1daeSBarry Smith     if (!flg) {
2845c6c1daeSBarry Smith       ierr = PetscStrcpy(fname, "matlaboutput.mat");
2859371c9d4SSatish Balay       if (ierr) {
2869371c9d4SSatish Balay         PetscError(PETSC_COMM_SELF, __LINE__, "PETSC_VIEWER_MATLAB_", __FILE__, PETSC_ERR_PLIB, PETSC_ERROR_REPEAT, " ");
2879371c9d4SSatish Balay         PetscFunctionReturn(NULL);
2889371c9d4SSatish Balay       }
2895c6c1daeSBarry Smith     }
2905c6c1daeSBarry Smith     ierr = PetscViewerMatlabOpen(ncomm, fname, FILE_MODE_WRITE, &viewer);
2919371c9d4SSatish Balay     if (ierr) {
2929371c9d4SSatish Balay       PetscError(PETSC_COMM_SELF, __LINE__, "PETSC_VIEWER_MATLAB_", __FILE__, PETSC_ERR_PLIB, PETSC_ERROR_REPEAT, " ");
2939371c9d4SSatish Balay       PetscFunctionReturn(NULL);
2949371c9d4SSatish Balay     }
2955c6c1daeSBarry Smith     ierr = PetscObjectRegisterDestroy((PetscObject)viewer);
2969371c9d4SSatish Balay     if (ierr) {
2979371c9d4SSatish Balay       PetscError(PETSC_COMM_SELF, __LINE__, "PETSC_VIEWER_MATLAB_", __FILE__, PETSC_ERR_PLIB, PETSC_ERROR_REPEAT, " ");
2989371c9d4SSatish Balay       PetscFunctionReturn(NULL);
2999371c9d4SSatish Balay     }
30047435625SJed Brown     ierr = MPI_Comm_set_attr(ncomm, Petsc_Viewer_Matlab_keyval, (void *)viewer);
3019371c9d4SSatish Balay     if (ierr) {
3029371c9d4SSatish Balay       PetscError(PETSC_COMM_SELF, __LINE__, "PETSC_VIEWER_MATLAB_", __FILE__, PETSC_ERR_PLIB, PETSC_ERROR_INITIAL, " ");
3039371c9d4SSatish Balay       PetscFunctionReturn(NULL);
3049371c9d4SSatish Balay     }
3055c6c1daeSBarry Smith   }
3065c6c1daeSBarry Smith   ierr = PetscCommDestroy(&ncomm);
3079371c9d4SSatish Balay   if (ierr) {
3089371c9d4SSatish Balay     PetscError(PETSC_COMM_SELF, __LINE__, "PETSC_VIEWER_MATLAB_", __FILE__, PETSC_ERR_PLIB, PETSC_ERROR_REPEAT, " ");
3099371c9d4SSatish Balay     PetscFunctionReturn(NULL);
3109371c9d4SSatish Balay   }
3115c6c1daeSBarry Smith   PetscFunctionReturn(viewer);
3125c6c1daeSBarry Smith }
313