Developer Reference for Intel® oneAPI Math Kernel Library for C

ID 766684
Date 7/13/2023
Public

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mkl_?getrfnp_compact

The routine computes the LU factorization, without pivoting, of a set of general, m x n matrices that have been stored in Compact format (see Compact Format).

Syntax

void mkl_sgetrfnp_compact (MKL_LAYOUT layout, MKL_INT m, MKL_INT n, float * ap, MKL_INT ldap, MKL_INT * info, MKL_COMPACT_PACK format, MKL_INT nm);

void mkl_dgetrfnp_compact (MKL_LAYOUT layout, MKL_INT m, MKL_INT n, double * ap, MKL_INT ldap, MKL_INT * info, MKL_COMPACT_PACK format, MKL_INT nm);

void mkl_cgetrfnp_compact (MKL_LAYOUT layout, MKL_INT m, MKL_INT n, float * ap, MKL_INT ldap, MKL_INT * info, MKL_COMPACT_PACK format, MKL_INT nm);

void mkl_zgetrfnp_compact (MKL_LAYOUT layout, MKL_INT m, MKL_INT n, double * ap, MKL_INT ldap, MKL_INT * info, MKL_COMPACT_PACK format, MKL_INT nm);

Description

The mkl_?getrfnp_compact routine calculates the LU factorizations of a set of nm general (m x n) matrices A, stored in Compact format, as Ac = Lc*Uc. The factorization (output) data will also be stored in Compact format.

NOTE:

Compact routines have some limitations; see Numerical Limitations.

Input Parameters

layout

Specifies whether two-dimensional array storage is row-major (MKL_ROW_MAJOR) or column-major (MKL_COL_MAJOR).

m
The number of rows of A; m ≥ 0.
n
The number of columns of A; n ≥ 0.
ap
Points to the beginning of the the array which stores nm Ac matrices.

See Compact Format for more details.

ldap
Leading dimension of Ac.
format
Specifies the format of the compact matrices. See Compact Format or mkl_get_format_compact for details.
nm
Total number of matrices stored in Compact format.

Application Notes:

Before calling this routine, mkl_?gepack_compact must be called. After calling this routine, mkl_?geunpack_compact should be called, unless another compact routine will be subsequently called for the Compact format matrices.

The approximate number of floating-point operations for real flavors is:

nm*(2/3)n3, if m = n,

nm*(1/3)n2(3m-n), if m > n,

nm*(1/3)m2(3n-m), if m < n.

The number of operations for complex flavors is four times greater. Directly after calling this routine, you can call the following:

mkl_?getrinp_compact, for computing the inverse of the nm input matrices in Compact format

Output Parameters

ap
On exit, Ac is overwritten by its factorization data. ap points to the beginning of nm Lc and Uc factors of Ac. The unit diagonal elements of Lc are not stored.
info
The parameter is not currently used in this routine. It is reserved for the future use.