Matrix Generator XLATMR | |
---|---|

Source: | LAPACK |

Discipline: | Numerical linear algebra |

Language: | Fortran |

Output format: | Matrix Market format, column major dense, column major dense packed |

DLATMR/ZLATMR generates random matrices of various types, and was developed to aid in testing the dense/structured sparse numerical algorithms in LAPACK. These routines are distributed as part of the LAPACK Test Suite, which is bundled with the complete library distribution, and, for convenience, are available here; see Links.

Interactive generation of DLATMR/ZLATMR matrices in Matrix Market format (with size restriction) and sample driving programs is available through the CGI Interface to DLATMR/ZLATMR.

Random dense/sparse matrices are generated in DLATMR/ZLATMR by applying the following sequence of operations:

- Generate a matrix A with random entries of distribution DIST which is symmetric if SYM='S', Hermitian if SYM='H', and nonsymmetric if SYM='N'.
- Set the diagonal to D, where D may be input or computed according to MODE, COND, DMAX and RSIGN as described below.
- Grade the matrix, if desired, from the left and/or right as specified by GRADE. The inputs DL, MODEL, CONDL, DR, MODER and CONDR also determine the grading as described below.
- Permute, if desired, the rows and/or columns as specified by PIVTNG and IPIVOT.
- Set random entries to zero, if desired, to get a random sparse matrix as specified by SPARSE.
- Make A a band matrix, if desired, by zeroing out the matrix outside a band of lower bandwidth KL and upper bandwidth KU.
- Scale A, if desired, to have maximum entry ANORM.
- Pack the matrix if desired. Options specified by PACK are:
- no packing
- store the lower half columnwise (if symmetric or Hermitian)

Parameters:

M | number of rows |

N | number of columns |

DIST | distribution of random values |

SYM | symmetry |

D | diagonal entries |

MODE | diagonal selection control |

COND | diagonal selection parameter |

DMAX | diagonal scaling parameter |

RSIGN | application of random sign |

GRADE | grade control |

DL | left grading matrix entries |

MODEL | left grading matrix selection |

CONDL | left grading matrix selection parameter |

DR | right grading matrix entries |

MODER | right grading matrix selection |

CONDR | right grading matrix selection parameter |

PIVTNG | pivoting selection control |

IPIVOT | pivoting selection parameter |

SPARSE | degree of sparsity |

KL | lower bandwidth |

KU | upper bandwidth |

ANORM | matrix scaling factor |

PACK | output format |

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Last change in this page: *Wed Sep 22 13:34:27 US/Eastern 2004*
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