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### [Lapack] lapack help

 ```sir/Madam, I want to use a routine from lapack SSYEV( JOBZ, UPLO, N, A, LDA, W, WORK, LWORK, INFO ) CHARACTER JOBZ, UPLO INTEGER INFO, LDA, LWORK, N REAL A( LDA, * ), W( * ), WORK( * ) PURPOSE SSYEV computes all eigenvalues and, optionally, eigenvectors of a real symmetric matrix A. ARGUMENTS JOBZ (input) CHARACTER*1 = 'N': Compute eigenvalues only; = 'V': Compute eigenvalues and eigenvectors. UPLO (input) CHARACTER*1 = 'U': Upper triangle of A is stored; = 'L': Lower triangle of A is stored. N (input) INTEGER The order of the matrix A. N >= 0. A (input/output) REAL array, dimension (LDA, N) On entry, the symmetric matrix A. If UPLO = 'U', the leading N-by-N upper triangular part of A contains the upper triangular part of the matrix A. If UPLO = 'L', the leading N-by-N lower triangular part of A contains the lower triangular part of the matrix A. On exit, if JOBZ = 'V', then if INFO = 0, A contains the orthonormal eigenvectors of the matrix A. If JOBZ = 'N', then on exit the lower triangle (if UPLO='L') or the upper tri- angle (if UPLO='U') of A, including the diagonal, is destroyed. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). W (output) REAL array, dimension (N) If INFO = 0, the eigenvalues in ascending order. WORK (workspace/output) REAL array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK. LWORK (input) INTEGER The length of the array WORK. LWORK >= max(1,3*N-1). For optimal efficiency, LWORK >= (NB+2)*N, where NB is the block- size for SSYTRD returned by ILAENV. If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value > 0: if INFO = i, the algorithm failed to converge; i off- diagonal elements of an intermediate tridiagonal form did not converge to zero. LAPACK driver routine (version 3November 2006 SSYEV(3) *here I do not understand LDA, WORK and LWORK. how to know what will be LWORK and LDA. * with best regards RAVINDRA PANKAJ -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.eecs.utk.edu/mailman/private/lapack/attachments/20100709/b2942739/attachment.html ```
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