Developer Reference for Intel® oneAPI Math Kernel Library for Fortran
?la_syrcond_x
Computes the infinity norm condition number of op(A)*diag(x) for symmetric indefinite matrices.
Syntax
call cla_syrcond_x ( uplo , n , a , lda , af , ldaf , ipiv , x , info , work , rwork )
call zla_syrcond_x ( uplo , n , a , lda , af , ldaf , ipiv , x , info , work , rwork )
Include Files
mkl.fi
Description
The function computes the infinity norm condition number of
op(A) * diag(x)
where the x is a COMPLEX vector for cla_syrcond_x and a DOUBLE COMPLEX vector for zla_syrcond_x .
Input Parameters
uplo
CHARACTER*1 . Must be ‘U’ or ‘L’ .
Specifies the triangle of A to store:
If uplo = 'U' , the upper triangle of A is stored,
If uplo = 'L' , the lower triangle of A is stored.
n
INTEGER . The number of linear equations, that is, the order of the matrix A ; n ≥ 0.
a
COMPLEX for cla_syrcond_c
DOUBLE COMPLEX for zla_syrcond_c
Array, DIMENSION (lda, *) . On entry, the n -by- n matrix A. The second dimension of a must be at least max(1,n) .
lda
INTEGER . The leading dimension of the array a . lda ≥ max(1,n) .
af
COMPLEX for cla_syrcond_c
DOUBLE COMPLEX for zla_syrcond_c
Array, DIMENSION (ldaf, *) . The block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by ?sytrf . The second dimension of af must be at least max(1,n) .
ldaf
INTEGER . The leading dimension of the array af . ldaf ≥ max(1,n) .
ipiv
INTEGER .
Array with DIMENSION n . Details of the interchanges and the block structure of D as determined by ?sytrf .
x
COMPLEX for cla_syrcond_c
DOUBLE COMPLEX for zla_syrcond_c
Array x with DIMENSION n . The vector x in the formula
op(A) * inv(diag(x)) .
work
COMPLEX for cla_syrcond_c
DOUBLE COMPLEX for zla_syrcond_c
Array DIMENSION 2* n . Workspace.
rwork
REAL for cla_syrcond_c
DOUBLE PRECISION for zla_syrcond_c
Array DIMENSION n . Workspace.
Output Parameters
info
INTEGER .
If info = 0, the execution is successful.
If i > 0, the i -th parameter is invalid.