Annotation of rpl/lapack/lapack/ztpttr.f, revision 1.1
1.1 ! bertrand 1: SUBROUTINE ZTPTTR( UPLO, N, AP, A, LDA, INFO )
! 2: *
! 3: * -- LAPACK routine (version 3.2) --
! 4: *
! 5: * -- Contributed by Julien Langou of the Univ. of Colorado Denver --
! 6: * -- November 2008 --
! 7: *
! 8: * -- LAPACK is a software package provided by Univ. of Tennessee, --
! 9: * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
! 10: *
! 11: * .. Scalar Arguments ..
! 12: CHARACTER UPLO
! 13: INTEGER INFO, N, LDA
! 14: * ..
! 15: * .. Array Arguments ..
! 16: COMPLEX*16 A( LDA, * ), AP( * )
! 17: * ..
! 18: *
! 19: * Purpose
! 20: * =======
! 21: *
! 22: * ZTPTTR copies a triangular matrix A from standard packed format (TP)
! 23: * to standard full format (TR).
! 24: *
! 25: * Arguments
! 26: * =========
! 27: *
! 28: * UPLO (input) CHARACTER
! 29: * = 'U': A is upper triangular.
! 30: * = 'L': A is lower triangular.
! 31: *
! 32: * N (input) INTEGER
! 33: * The order of the matrix A. N >= 0.
! 34: *
! 35: * AP (input) COMPLEX*16 array, dimension ( N*(N+1)/2 ),
! 36: * On entry, the upper or lower triangular matrix A, packed
! 37: * columnwise in a linear array. The j-th column of A is stored
! 38: * in the array AP as follows:
! 39: * if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j;
! 40: * if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = A(i,j) for j<=i<=n.
! 41: *
! 42: * A (output) COMPLEX*16 array, dimension ( LDA, N )
! 43: * On exit, the triangular matrix A. If UPLO = 'U', the leading
! 44: * N-by-N upper triangular part of A contains the upper
! 45: * triangular part of the matrix A, and the strictly lower
! 46: * triangular part of A is not referenced. If UPLO = 'L', the
! 47: * leading N-by-N lower triangular part of A contains the lower
! 48: * triangular part of the matrix A, and the strictly upper
! 49: * triangular part of A is not referenced.
! 50: *
! 51: * LDA (input) INTEGER
! 52: * The leading dimension of the array A. LDA >= max(1,N).
! 53: *
! 54: * INFO (output) INTEGER
! 55: * = 0: successful exit
! 56: * < 0: if INFO = -i, the i-th argument had an illegal value
! 57: *
! 58: * =====================================================================
! 59: *
! 60: * .. Parameters ..
! 61: * ..
! 62: * .. Local Scalars ..
! 63: LOGICAL LOWER
! 64: INTEGER I, J, K
! 65: * ..
! 66: * .. External Functions ..
! 67: LOGICAL LSAME
! 68: EXTERNAL LSAME
! 69: * ..
! 70: * .. External Subroutines ..
! 71: EXTERNAL XERBLA
! 72: * ..
! 73: * .. Executable Statements ..
! 74: *
! 75: * Test the input parameters.
! 76: *
! 77: INFO = 0
! 78: LOWER = LSAME( UPLO, 'L' )
! 79: IF( .NOT.LOWER .AND. .NOT.LSAME( UPLO, 'U' ) ) THEN
! 80: INFO = -1
! 81: ELSE IF( N.LT.0 ) THEN
! 82: INFO = -2
! 83: ELSE IF( LDA.LT.MAX( 1, N ) ) THEN
! 84: INFO = -5
! 85: END IF
! 86: IF( INFO.NE.0 ) THEN
! 87: CALL XERBLA( 'ZTPTTR', -INFO )
! 88: RETURN
! 89: END IF
! 90: *
! 91: IF( LOWER ) THEN
! 92: K = 0
! 93: DO J = 1, N
! 94: DO I = J, N
! 95: K = K + 1
! 96: A( I, J ) = AP( K )
! 97: END DO
! 98: END DO
! 99: ELSE
! 100: K = 0
! 101: DO J = 1, N
! 102: DO I = 1, J
! 103: K = K + 1
! 104: A( I, J ) = AP( K )
! 105: END DO
! 106: END DO
! 107: END IF
! 108: *
! 109: *
! 110: RETURN
! 111: *
! 112: * End of ZTPTTR
! 113: *
! 114: END
CVSweb interface <joel.bertrand@systella.fr>