tbcon#

Functions

void stbcon(
    const char*          norm,
    const char*          uplo,
    const char*          diag,
    const INT            n,
    const INT            kd,
    const f32*  restrict AB,
    const INT            ldab,
          f32*           rcond,
          f32*  restrict work,
          INT*  restrict iwork,
          INT*           info
);
void stbcon(const char *norm, const char *uplo, const char *diag, const INT n, const INT kd, const f32 *restrict AB, const INT ldab, f32 *rcond, f32 *restrict work, INT *restrict iwork, INT *info)#

STBCON estimates the reciprocal of the condition number of a triangular band matrix A, in either the 1-norm or the infinity-norm.

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

Parameters

in
norm

= ‘1’ or ‘O’: 1-norm = ‘I’: Infinity-norm

in
uplo

= ‘U’: A is upper triangular = ‘L’: A is lower triangular

in
diag

= ‘N’: A is non-unit triangular = ‘U’: A is unit triangular

in
n

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

in
kd

The number of superdiagonals or subdiagonals. kd >= 0.

in
AB

The triangular band matrix A. Array of dimension (ldab, n).

in
ldab

The leading dimension of AB. ldab >= kd+1.

out
rcond

The reciprocal of the condition number.

out
work

Workspace array of dimension (3*n).

out
iwork

Integer workspace array of dimension (n).

out
info

  • = 0: successful exit

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

Functions

void dtbcon(
    const char*          norm,
    const char*          uplo,
    const char*          diag,
    const INT            n,
    const INT            kd,
    const f64*  restrict AB,
    const INT            ldab,
          f64*           rcond,
          f64*  restrict work,
          INT*  restrict iwork,
          INT*           info
);
void dtbcon(const char *norm, const char *uplo, const char *diag, const INT n, const INT kd, const f64 *restrict AB, const INT ldab, f64 *rcond, f64 *restrict work, INT *restrict iwork, INT *info)#

DTBCON estimates the reciprocal of the condition number of a triangular band matrix A, in either the 1-norm or the infinity-norm.

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

Parameters

in
norm

= ‘1’ or ‘O’: 1-norm = ‘I’: Infinity-norm

in
uplo

= ‘U’: A is upper triangular = ‘L’: A is lower triangular

in
diag

= ‘N’: A is non-unit triangular = ‘U’: A is unit triangular

in
n

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

in
kd

The number of superdiagonals or subdiagonals. kd >= 0.

in
AB

The triangular band matrix A. Array of dimension (ldab, n).

in
ldab

The leading dimension of AB. ldab >= kd+1.

out
rcond

The reciprocal of the condition number.

out
work

Workspace array of dimension (3*n).

out
iwork

Integer workspace array of dimension (n).

out
info

  • = 0: successful exit

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

Functions

void ctbcon(
    const char*          norm,
    const char*          uplo,
    const char*          diag,
    const INT            n,
    const INT            kd,
    const c64*  restrict AB,
    const INT            ldab,
          f32*           rcond,
          c64*  restrict work,
          f32*  restrict rwork,
          INT*           info
);
void ctbcon(const char *norm, const char *uplo, const char *diag, const INT n, const INT kd, const c64 *restrict AB, const INT ldab, f32 *rcond, c64 *restrict work, f32 *restrict rwork, INT *info)#

CTBCON estimates the reciprocal of the condition number of a triangular band matrix A, in either the 1-norm or the infinity-norm.

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

Parameters

in
norm

= ‘1’ or ‘O’: 1-norm = ‘I’: Infinity-norm

in
uplo

= ‘U’: A is upper triangular = ‘L’: A is lower triangular

in
diag

= ‘N’: A is non-unit triangular = ‘U’: A is unit triangular

in
n

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

in
kd

The number of superdiagonals or subdiagonals. kd >= 0.

in
AB

The triangular band matrix A. Array of dimension (ldab, n).

in
ldab

The leading dimension of AB. ldab >= kd+1.

out
rcond

The reciprocal of the condition number.

out
work

Complex workspace array of dimension (2*n).

out
rwork

Single precision workspace array of dimension (n).

out
info

  • = 0: successful exit

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

Functions

void ztbcon(
    const char*          norm,
    const char*          uplo,
    const char*          diag,
    const INT            n,
    const INT            kd,
    const c128* restrict AB,
    const INT            ldab,
          f64*           rcond,
          c128* restrict work,
          f64*  restrict rwork,
          INT*           info
);
void ztbcon(const char *norm, const char *uplo, const char *diag, const INT n, const INT kd, const c128 *restrict AB, const INT ldab, f64 *rcond, c128 *restrict work, f64 *restrict rwork, INT *info)#

ZTBCON estimates the reciprocal of the condition number of a triangular band matrix A, in either the 1-norm or the infinity-norm.

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

Parameters

in
norm

= ‘1’ or ‘O’: 1-norm = ‘I’: Infinity-norm

in
uplo

= ‘U’: A is upper triangular = ‘L’: A is lower triangular

in
diag

= ‘N’: A is non-unit triangular = ‘U’: A is unit triangular

in
n

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

in
kd

The number of superdiagonals or subdiagonals. kd >= 0.

in
AB

The triangular band matrix A. Array of dimension (ldab, n).

in
ldab

The leading dimension of AB. ldab >= kd+1.

out
rcond

The reciprocal of the condition number.

out
work

Complex workspace array of dimension (2*n).

out
rwork

Double precision workspace array of dimension (n).

out
info

  • = 0: successful exit

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

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