Visible to Intel only — GUID: GUID-9544C788-A2E3-4B56-94CA-04C81C15ADF0
Visible to Intel only — GUID: GUID-9544C788-A2E3-4B56-94CA-04C81C15ADF0
mkl_?getrfnp
Computes the LU factorization of a general m-by-n matrix without pivoting.
Syntax
call mkl_sgetrfnp( m, n, a, lda, info )
call mkl_dgetrfnp( m, n, a, lda, info )
call mkl_cgetrfnp( m, n, a, lda, info )
call mkl_zgetrfnp( m, n, a, lda, info )
Include Files
mkl.fi
Description
The routine computes the LU factorization of a general m-by-n matrix A as
A = L*U,
where L is lower triangular with unit-diagonal elements (lower trapezoidal if m > n) and U is upper triangular (upper trapezoidal if m < n). The routine does not use pivoting.
Input Parameters
m |
INTEGER. The number of rows in the matrix A (m≥ 0). |
n |
INTEGER. The number of columns in A; n≥ 0. |
a |
REAL for mkl_sgetrfnp DOUBLE PRECISION for mkl_dgetrfnp COMPLEX for mkl_cgetrfnp DOUBLE COMPLEX for mkl_zgetrfnp. Array, size lda by *. Contains the matrix A. The second dimension of a must be at least max(1, n). |
lda |
INTEGER. The leading dimension of array a. |
Output Parameters
a |
Overwritten by L and U. The unit diagonal elements of L are not stored. |
info |
INTEGER. If info=0, the execution is successful. If info = -i, the i-th parameter had an illegal value. If info = i, uii is 0. The factorization has been completed, but U is exactly singular. Division by 0 will occur if you use the factor U for solving a system of linear equations. |
Application Notes
The approximate number of floating-point operations for real flavors is
(2/3)n3 |
If m = n, |
(1/3)n2(3m-n) |
If m>n, |
(1/3)m2(3n-m) |
If m<n. |
The number of operations for complex flavors is four times greater.
After calling this routine with m = n, you can call the following:
- mkl_?getrinp
-
to compute the inverse of A