hpcon#

Functions

void chpcon(
    const char*          uplo,
    const INT            n,
    const c64*  restrict AP,
    const INT*  restrict ipiv,
    const f32            anorm,
          f32*           rcond,
          c64*  restrict work,
          INT*           info
);
void chpcon(const char *uplo, const INT n, const c64 *restrict AP, const INT *restrict ipiv, const f32 anorm, f32 *rcond, c64 *restrict work, INT *info)#

CHPCON estimates the reciprocal of the condition number (in the 1-norm) of a complex Hermitian packed matrix A using the factorization A = U*D*U**H or A = L*D*L**H computed by CHPTRF.

An estimate is obtained for norm(inv(A)), and the reciprocal of the condition number is computed as RCOND = 1 / (ANORM * norm(inv(A))).

Parameters

in
uplo

= ‘U’: Upper triangular, form is A = U*D*U**H = ‘L’: Lower triangular, form is A = L*D*L**H

in
n

The order of the matrix A. n >= 0.

in
AP

The block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by CHPTRF, stored as a packed triangular matrix. Array of dimension (n*(n+1)/2).

in
ipiv

Details of the interchanges and the block structure of D as determined by CHPTRF. Array of dimension (n).

in
anorm

The 1-norm of the original matrix A.

out
rcond

The reciprocal of the condition number of the matrix A.

out
work

Workspace array of dimension (2*n).

out
info

  • = 0: successful exit

  • < 0: if info = -i, the i-th argument had an illegal value

Functions

void zhpcon(
    const char*          uplo,
    const INT            n,
    const c128* restrict AP,
    const INT*  restrict ipiv,
    const f64            anorm,
          f64*           rcond,
          c128* restrict work,
          INT*           info
);
void zhpcon(const char *uplo, const INT n, const c128 *restrict AP, const INT *restrict ipiv, const f64 anorm, f64 *rcond, c128 *restrict work, INT *info)#

ZHPCON estimates the reciprocal of the condition number (in the 1-norm) of a complex Hermitian packed matrix A using the factorization A = U*D*U**H or A = L*D*L**H computed by ZHPTRF.

An estimate is obtained for norm(inv(A)), and the reciprocal of the condition number is computed as RCOND = 1 / (ANORM * norm(inv(A))).

Parameters

in
uplo

= ‘U’: Upper triangular, form is A = U*D*U**H = ‘L’: Lower triangular, form is A = L*D*L**H

in
n

The order of the matrix A. n >= 0.

in
AP

The block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by ZHPTRF, stored as a packed triangular matrix. Array of dimension (n*(n+1)/2).

in
ipiv

Details of the interchanges and the block structure of D as determined by ZHPTRF. Array of dimension (n).

in
anorm

The 1-norm of the original matrix A.

out
rcond

The reciprocal of the condition number of the matrix A.

out
work

Workspace array of dimension (2*n).

out
info

  • = 0: successful exit

  • < 0: if info = -i, the i-th argument had an illegal value