ansys.mapdl.core.Mapdl.dmat#

Mapdl.dmat(matrix='', type_='', method='', val1='', val2='', val3='', val4='', val5='', **kwargs)#

Creates a dense matrix.

Mechanical APDL Command: *DMAT

Parameters:
matrixstr

Name used to identify the matrix. Must be specified.

type_str

Matrix type:

  • D - Double precision real values (default).

  • Z - Complex double precision values.

  • I - Integer values.

methodstr

Method used to create the matrix:

  • ALLOC - Allocate space for a matrix (default).

  • RESIZE - Resize an existing matrix to new row and column dimensions. Values are kept from the original matrix. If the dimensions specified by Val1 (rows) and Val2 (columns) are greater than the original matrix size, the additional entries are assigned a value of zero.

  • COPY - Copy an existing matrix.

  • LINK - Link to an existing matrix. The memory will be shared between the original matrix and the new matrix. This is useful for manipulating a submatrix of a larger matrix. The Val1 through Val5 arguments will be used to specify the lower and upper bounds of row and column numbers from the original matrix.

  • IMPORT - Import the matrix from a file.

val1str

Name of the original matrix.

val2str

First column number (defaults to 1).

val3str

Last column number (defaults to the maximum column number of the original matrix).

val4str

First row number (defaults to 1).

val5str

Last row number (defaults to the maximum row number of the original matrix).

Notes

Warning

This function contains specificities regarding the argument definitions. Please refer to the command documentation for further explanations.

Argument Descriptions

  • matrix : str - Name used to identify the matrix. Must be specified.

  • type_ : str - Matrix type:

    • D - Double precision real values (default).

    • Z - Complex double precision values.

    • I - Integer values.

  • method : str - Method used to create the matrix:

    • ALLOC - Allocate space for a matrix (default).

    • RESIZE - Resize an existing matrix to new row and column dimensions. Values are kept from the original matrix. If the dimensions specified by Val1 (rows) and Val2 (columns) are greater than the original matrix size, the additional entries are assigned a value of zero.

    • COPY - Copy an existing matrix.

    • LINK - Link to an existing matrix. The memory will be shared between the original matrix and the new matrix. This is useful for manipulating a submatrix of a larger matrix. The Val1 through Val5 arguments will be used to specify the lower and upper bounds of row and column numbers from the original matrix.

    • IMPORT - Import the matrix from a file.

  • val1, val2, val3, val4, val5 : str - Additional input. The meaning of Val1 through Val5 will vary depending on the specified Method. See details below.

The following Valx fields are used with Method = ALLOC or Method = RESIZE:

  • val1 : str - Number of rows in the matrix.

  • val2 : str - Number of columns in the matrix.

  • val3 : str - Memory allocation type (used only with Method = ALLOC):

    • INCORE - In-core memory allocation (default).

    • OUTOFCORE - Out-of-core memory allocation.

The following Valx fields are used with Method = COPY:

  • val1 : str - Name of the matrix to copy.

  • val2 : str - Method used for copying the matrix:

    • TRANS - Transpose the original matrix. Val3 and Val4 are ignored.

    • REAL - Copy the real part to the output matrix. This option only applies when copying a complex value matrix to a real value matrix. Val3 and Val4 are ignored.

    • IMAG - Copy the imaginary part to the output matrix. This option only applies when copying a complex value matrix to a real value matrix. Val3 and Val4 are ignored.

    • EXTRACT - Extract a submatrix based on row and column numbers specified by Val3 and Val4.

  • val3 : str - Name of integer vector ( vec ) containing row numbers. If no vector is specified, defaults to all rows.

  • val4 : str - Name of integer vector ( vec ) containing column numbers. If no vector is specified, defaults to all columns.

The following Valx fields are used with Method = LINK:

  • val1 : str - Name of the original matrix.

  • val2 : str - First column number (defaults to 1).

  • val3 : str - Last column number (defaults to the maximum column number of the original matrix).

  • val4 : str - First row number (defaults to 1).

  • val5 : str - Last row number (defaults to the maximum row number of the original matrix).

The following table describes the Valx fields used with Method = IMPORT:

This command contains some tables and extra information which can be inspected in the original documentation pointed above.

This command allows you to create a dense matrix. To create a sparse matrix, use the smat command. smat is recommended for large matrices obtained from the .FULL or .HBMAT file. Refer to the hbmat command documentation for more information about .FULL file contents.

Use the vec command to create a vector.

For very large matrices, use the OUTOFCORE option ( Method = ALLOC or COPY) to keep some of the matrix on disk if there is insufficient memory.

When importing a dense matrix from a DMIG file, you can define the formatting of the file using the Val3 and Val4 fields. Here are a few different example of formats:

  • A LARGE field format file (using Val3 = LARGE):

 ...    DMIG*   KAAX                          21               2    *                     21
1-2.261491337E+08...

  • A FREE field format file with blank separators (using Val4 = S):

...    DMIG stiff 1 2 1 2 29988.    1 6 149940. 2 2 -29988.    2 6 149940....

  • A FREE field format file with a comma separator (using Val4 = ,):

...    DMIG,KF,22321,3,,22321,2,-5.00E+6    DMIG,KF,22320,3,,22320,2,-5.00E+6...

Requirement when importing matrices from a Nastran DMIG file: To ensure that the .sub file is properly generated from matrices imported from Nastran DMIG file, the generalized coordinates for a CMS superelement (SPOINTS in Nastran) must appear last (have highest ID number).

Example Usage APDL Math Examples