petsc-3.7.3 2016-07-24
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# MatView

Visualizes a matrix object.

### Synopsis

    #include "petscmat.h"
    PetscErrorCode MatView(Mat mat,PetscViewer viewer)

Collective on Mat

### Input Parameters

| mat | - the matrix
| viewer | - visualization context

### Notes

The available visualization contexts include

| PETSC_VIEWER_STDOUT_SELF | - for sequential matrices
| PETSC_VIEWER_STDOUT_WORLD | - for parallel matrices created on PETSC_COMM_WORLD
| PETSC_VIEWER_STDOUT_(comm) | - for matrices created on MPI communicator comm
| PETSC_VIEWER_DRAW_WORLD | - graphical display of nonzero structure

The user can open alternative visualization contexts with

| PetscViewerASCIIOpen() | - Outputs matrix to a specified file
| PetscViewerBinaryOpen() | - Outputs matrix in binary to a specified file; corresponding input uses MatLoad()
| PetscViewerDrawOpen() | - Outputs nonzero matrix structure to an X window display
| PetscViewerSocketOpen() | - Outputs matrix to Socket viewer. Currently only the sequential dense and AIJ matrix types support the Socket viewer.

The user can call PetscViewerPushFormat() to specify the output format of ASCII printed objects (when using PETSC_VIEWER_STDOUT_SELF, PETSC_VIEWER_STDOUT_WORLD and PetscViewerASCIIOpen). Available formats include

| PETSC_VIEWER_DEFAULT | - default, prints matrix contents
| PETSC_VIEWER_ASCII_MATLAB | - prints matrix contents in Matlab format
| PETSC_VIEWER_ASCII_DENSE | - prints entire matrix including zeros
| PETSC_VIEWER_ASCII_COMMON | - prints matrix contents, using a sparse format common among all matrix types
| PETSC_VIEWER_ASCII_IMPL | - prints matrix contents, using an implementation-specific format (which is in many cases the same as the default)
| PETSC_VIEWER_ASCII_INFO | - prints basic information about the matrix size and structure (not the matrix entries)
| PETSC_VIEWER_ASCII_INFO_DETAIL | - prints more detailed information about the matrix structure

### Options Database Keys

| -mat_view ::ascii_info | - Prints info on matrix at conclusion of MatEndAssembly()
| -mat_view ::ascii_info_detail | - Prints more detailed info
| -mat_view | - Prints matrix in ASCII format
| -mat_view ::ascii_matlab | - Prints matrix in Matlab format
| -mat_view draw | - PetscDraws nonzero structure of matrix, using MatView() and PetscDrawOpenX().
| -display <name> | - Sets display name (default is host)
| -draw_pause <sec> | - Sets number of seconds to pause after display
| -mat_view socket | - Sends matrix to socket, can be accessed from Matlab (see Users-Manual: Chapter 11 Using MATLAB with PETSc for details)
| -viewer_socket_machine <machine> | -
| -viewer_socket_port <port> | -
| -mat_view binary | - save matrix to file in binary format
| -viewer_binary_filename <name> | -

Notes: see the manual page for MatLoad() for the exact format of the binary file when the binary viewer is used.

See share/petsc/matlab/PetscBinaryRead.m for a Matlab code that can read in the binary file when the binary viewer is used.

One can use '-mat_view draw -draw_pause -1' to pause the graphical display of matrix nonzero structure.

### And then use the following mouse functions

left mouse: zoom in middle mouse: zoom out right mouse: continue with the simulation

### See Also

PetscViewerPushFormat(), PetscViewerASCIIOpen(), PetscViewerDrawOpen(),
PetscViewerSocketOpen(), PetscViewerBinaryOpen(), MatLoad()

Level:beginner
Location: src/mat/interface/matrix.c
Index of all Mat routines
Table of Contents for all manual pages
Index of all manual pages

### Examples

src/vec/vec/examples/tutorials/ex6.c.html
src/mat/examples/tutorials/ex8.c.html
src/mat/examples/tutorials/ex11.c.html
src/mat/examples/tutorials/ex12.c.html
src/mat/examples/tutorials/ex16.c.html
src/mat/examples/tutorials/ex17.c.html
src/ksp/pc/examples/tutorials/ex2.c.html
src/ksp/ksp/examples/tutorials/ex4.c.html
src/ksp/ksp/examples/tutorials/ex10.c.html
src/ksp/ksp/examples/tutorials/ex28.c.html
src/ksp/ksp/examples/tutorials/ex54.c.html