diff options
Diffstat (limited to 'SRC/dspgvx.f')
| -rw-r--r-- | SRC/dspgvx.f | 24 |
1 files changed, 8 insertions, 16 deletions
diff --git a/SRC/dspgvx.f b/SRC/dspgvx.f index f83eb174..178e0d1c 100644 --- a/SRC/dspgvx.f +++ b/SRC/dspgvx.f @@ -98,8 +98,7 @@ *> is stored in the array AP as follows: *> if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j; *> if UPLO = 'L', AP(i + (j-1)*(2*n-j)/2) = A(i,j) for j<=i<=n. -*> \endverbatim -*> \verbatim +*> *> On exit, the contents of AP are destroyed. *> \endverbatim *> @@ -111,8 +110,7 @@ *> is stored in the array BP as follows: *> if UPLO = 'U', BP(i + (j-1)*j/2) = B(i,j) for 1<=i<=j; *> if UPLO = 'L', BP(i + (j-1)*(2*n-j)/2) = B(i,j) for j<=i<=n. -*> \endverbatim -*> \verbatim +*> *> On exit, the triangular factor U or L from the Cholesky *> factorization B = U**T*U or B = L*L**T, in the same storage *> format as B. @@ -126,8 +124,7 @@ *> \param[in] VU *> \verbatim *> VU is DOUBLE PRECISION -*> \endverbatim -*> \verbatim +*> *> If RANGE='V', the lower and upper bounds of the interval to *> be searched for eigenvalues. VL < VU. *> Not referenced if RANGE = 'A' or 'I'. @@ -141,8 +138,7 @@ *> \param[in] IU *> \verbatim *> IU is INTEGER -*> \endverbatim -*> \verbatim +*> *> If RANGE='I', the indices (in ascending order) of the *> smallest and largest eigenvalues to be returned. *> 1 <= IL <= IU <= N, if N > 0; IL = 1 and IU = 0 if N = 0. @@ -156,17 +152,14 @@ *> An approximate eigenvalue is accepted as converged *> when it is determined to lie in an interval [a,b] *> of width less than or equal to -*> \endverbatim -*> \verbatim +*> *> ABSTOL + EPS * max( |a|,|b| ) , -*> \endverbatim -*> \verbatim +*> *> where EPS is the machine precision. If ABSTOL is less than *> or equal to zero, then EPS*|T| will be used in its place, *> where |T| is the 1-norm of the tridiagonal matrix obtained *> by reducing A to tridiagonal form. -*> \endverbatim -*> \verbatim +*> *> Eigenvalues will be computed most accurately when ABSTOL is *> set to twice the underflow threshold 2*DLAMCH('S'), not zero. *> If this routine returns with INFO>0, indicating that some @@ -199,8 +192,7 @@ *> The eigenvectors are normalized as follows: *> if ITYPE = 1 or 2, Z**T*B*Z = I; *> if ITYPE = 3, Z**T*inv(B)*Z = I. -*> \endverbatim -*> \verbatim +*> *> If an eigenvector fails to converge, then that column of Z *> contains the latest approximation to the eigenvector, and the *> index of the eigenvector is returned in IFAIL. |