Developer Reference for Intel® oneAPI Math Kernel Library for Fortran
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?la_gerpvgrw
Computes the reciprocal pivot growth factor norm(A)/norm(U) for a general matrix.
Syntax
call sla_gerpvgrw( n, ncols, a, lda, af, ldaf )
call dla_gerpvgrw( n, ncols, a, lda, af, ldaf )
call cla_gerpvgrw( n, ncols, a, lda, af, ldaf )
call zla_gerpvgrw( n, ncols, a, lda, af, ldaf )
Include Files
- mkl.fi
 
Description
The ?la_gerpvgrw routine computes the reciprocal pivot growth factor norm(A)/norm(U). The max absolute element norm is used. If this is much less than 1, the stability of the LU factorization of the equilibrated matrix A could be poor. This also means that the solution X, estimated condition numbers, and error bounds could be unreliable.
Input Parameters
n  |  
      INTEGER. The number of linear equations, the order of the matrix A; n≥ 0.  |  
     
ncols  |  
      INTEGER. The number of columns of the matrix A; ncols≥ 0.  |  
     
a, af  |  
      REAL for sla_gerpvgrw DOUBLE PRECISION for dla_gerpvgrw COMPLEX for cla_gerpvgrw DOUBLE COMPLEX for zla_gerpvgrw. Arrays: a(lda,*), af(ldaf,*). The array a contains the input n-by-n matrix A. The second dimension of a must be at least max(1,n). The array af contains the factors L and U from the factorization triangular factor L or U from the Cholesky factorization A = P*L*U as computed by ?getrf. The second dimension of af must be at least max(1,n).  |  
     
lda  |  
      INTEGER. The leading dimension of a; lda≥ max(1,n).  |  
     
ldaf  |  
      INTEGER. The leading dimension of af; ldaf≥ max(1,n).  |