heequb#
Functions
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void cheequb(const char *uplo, const INT n, const c64 *restrict A, const INT lda, f32 *restrict S, f32 *scond, f32 *amax, c64 *restrict work, INT *info)#
CHEEQUB computes row and column scalings intended to equilibrate a Hermitian matrix A (with respect to the Euclidean norm) and reduce its condition number.
The scale factors S are computed by the BIN algorithm (see references) so that the scaled matrix B with elements B(i,j) = S(i)*A(i,j)*S(j) has a condition number within a factor N of the smallest possible condition number over all possible diagonal scalings.
Parameters
inuploSpecifies whether the upper or lower triangular part of the Hermitian matrix A is stored. = ‘U’: Upper triangle of A is stored = ‘L’: Lower triangle of A is stored
innThe order of the matrix A. n >= 0.
inAComplex*16 array, dimension (lda, n). The N-by-N Hermitian matrix whose scaling factors are to be computed.
inldaThe leading dimension of the array A. lda >= max(1,n).
outSSingle precision array, dimension (n). If info = 0, S contains the scale factors for A.
outscondIf info = 0, S contains the ratio of the smallest S(i) to the largest S(i). If scond >= 0.1 and amax is neither too large nor too small, it is not worth scaling by S.
outamaxLargest absolute value of any matrix element. If amax is very close to overflow or very close to underflow, the matrix should be scaled.
outworkComplex*16 array, dimension (2*n).
outinfo= 0: successful exit
< 0: if info = -i, the i-th argument had an illegal value
> 0: if info = i, the i-th diagonal element is nonpositive.
void cheequb(
const char* uplo,
const INT n,
const c64* restrict A,
const INT lda,
f32* restrict S,
f32* scond,
f32* amax,
c64* restrict work,
INT* info
);
Functions
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void zheequb(const char *uplo, const INT n, const c128 *restrict A, const INT lda, f64 *restrict S, f64 *scond, f64 *amax, c128 *restrict work, INT *info)#
ZHEEQUB computes row and column scalings intended to equilibrate a Hermitian matrix A (with respect to the Euclidean norm) and reduce its condition number.
The scale factors S are computed by the BIN algorithm (see references) so that the scaled matrix B with elements B(i,j) = S(i)*A(i,j)*S(j) has a condition number within a factor N of the smallest possible condition number over all possible diagonal scalings.
Parameters
inuploSpecifies whether the upper or lower triangular part of the Hermitian matrix A is stored. = ‘U’: Upper triangle of A is stored = ‘L’: Lower triangle of A is stored
innThe order of the matrix A. n >= 0.
inAComplex*16 array, dimension (lda, n). The N-by-N Hermitian matrix whose scaling factors are to be computed.
inldaThe leading dimension of the array A. lda >= max(1,n).
outSDouble precision array, dimension (n). If info = 0, S contains the scale factors for A.
outscondIf info = 0, S contains the ratio of the smallest S(i) to the largest S(i). If scond >= 0.1 and amax is neither too large nor too small, it is not worth scaling by S.
outamaxLargest absolute value of any matrix element. If amax is very close to overflow or very close to underflow, the matrix should be scaled.
outworkComplex*16 array, dimension (2*n).
outinfo= 0: successful exit
< 0: if info = -i, the i-th argument had an illegal value
> 0: if info = i, the i-th diagonal element is nonpositive.
void zheequb(
const char* uplo,
const INT n,
const c128* restrict A,
const INT lda,
f64* restrict S,
f64* scond,
f64* amax,
c128* restrict work,
INT* info
);