.TH "SRC/sspgst.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME SRC/sspgst.f .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBsspgst\fP (itype, uplo, n, ap, bp, info)" .br .RI "\fBSSPGST\fP " .in -1c .SH "Function/Subroutine Documentation" .PP .SS "subroutine sspgst (integer itype, character uplo, integer n, real, dimension( * ) ap, real, dimension( * ) bp, integer info)" .PP \fBSSPGST\fP .PP \fBPurpose:\fP .RS 4 .PP .nf !> !> SSPGST reduces a real symmetric-definite generalized eigenproblem !> to standard form, using packed storage\&. !> !> If ITYPE = 1, the problem is A*x = lambda*B*x, !> and A is overwritten by inv(U**T)*A*inv(U) or inv(L)*A*inv(L**T) !> !> If ITYPE = 2 or 3, the problem is A*B*x = lambda*x or !> B*A*x = lambda*x, and A is overwritten by U*A*U**T or L**T*A*L\&. !> !> B must have been previously factorized as U**T*U or L*L**T by SPPTRF\&. !> .fi .PP .RE .PP \fBParameters\fP .RS 4 \fIITYPE\fP .PP .nf !> ITYPE is INTEGER !> = 1: compute inv(U**T)*A*inv(U) or inv(L)*A*inv(L**T); !> = 2 or 3: compute U*A*U**T or L**T*A*L\&. !> .fi .PP .br \fIUPLO\fP .PP .nf !> UPLO is CHARACTER*1 !> = 'U': Upper triangle of A is stored and B is factored as !> U**T*U; !> = 'L': Lower triangle of A is stored and B is factored as !> L*L**T\&. !> .fi .PP .br \fIN\fP .PP .nf !> N is INTEGER !> The order of the matrices A and B\&. N >= 0\&. !> .fi .PP .br \fIAP\fP .PP .nf !> AP is REAL array, dimension (N*(N+1)/2) !> On entry, the upper or lower triangle of the symmetric matrix !> A, packed columnwise in a linear array\&. The j-th column of A !> 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)*(2n-j)/2) = A(i,j) for j<=i<=n\&. !> !> On exit, if INFO = 0, the transformed matrix, stored in the !> same format as A\&. !> .fi .PP .br \fIBP\fP .PP .nf !> BP is REAL array, dimension (N*(N+1)/2) !> The triangular factor from the Cholesky factorization of B, !> stored in the same format as A, as returned by SPPTRF\&. !> .fi .PP .br \fIINFO\fP .PP .nf !> INFO is INTEGER !> = 0: successful exit !> < 0: if INFO = -i, the i-th argument had an illegal value !> .fi .PP .RE .PP \fBAuthor\fP .RS 4 Univ\&. of Tennessee .PP Univ\&. of California Berkeley .PP Univ\&. of Colorado Denver .PP NAG Ltd\&. .RE .PP .PP Definition at line \fB112\fP of file \fBsspgst\&.f\fP\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.