Developer Reference for Intel® oneAPI Math Kernel Library for Fortran
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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