LAPACK 3.11.0
LAPACK: Linear Algebra PACKage

◆ dlattb()

subroutine dlattb ( integer  IMAT,
character  UPLO,
character  TRANS,
character  DIAG,
integer, dimension( 4 )  ISEED,
integer  N,
integer  KD,
double precision, dimension( ldab, * )  AB,
integer  LDAB,
double precision, dimension( * )  B,
double precision, dimension( * )  WORK,
integer  INFO 
)

DLATTB

Purpose:
 DLATTB generates a triangular test matrix in 2-dimensional storage.
 IMAT and UPLO uniquely specify the properties of the test matrix,
 which is returned in the array A.
Parameters
[in]IMAT
          IMAT is INTEGER
          An integer key describing which matrix to generate for this
          path.
[in]UPLO
          UPLO is CHARACTER*1
          Specifies whether the matrix A will be upper or lower
          triangular.
          = 'U':  Upper triangular
          = 'L':  Lower triangular
[in]TRANS
          TRANS is CHARACTER*1
          Specifies whether the matrix or its transpose will be used.
          = 'N':  No transpose
          = 'T':  Transpose
          = 'C':  Conjugate transpose (= transpose)
[out]DIAG
          DIAG is CHARACTER*1
          Specifies whether or not the matrix A is unit triangular.
          = 'N':  Non-unit triangular
          = 'U':  Unit triangular
[in,out]ISEED
          ISEED is INTEGER array, dimension (4)
          The seed vector for the random number generator (used in
          DLATMS).  Modified on exit.
[in]N
          N is INTEGER
          The order of the matrix to be generated.
[in]KD
          KD is INTEGER
          The number of superdiagonals or subdiagonals of the banded
          triangular matrix A.  KD >= 0.
[out]AB
          AB is DOUBLE PRECISION array, dimension (LDAB,N)
          The upper or lower triangular banded matrix A, stored in the
          first KD+1 rows of AB.  Let j be a column of A, 1<=j<=n.
          If UPLO = 'U', AB(kd+1+i-j,j) = A(i,j) for max(1,j-kd)<=i<=j.
          If UPLO = 'L', AB(1+i-j,j)    = A(i,j) for j<=i<=min(n,j+kd).
[in]LDAB
          LDAB is INTEGER
          The leading dimension of the array AB.  LDAB >= KD+1.
[out]B
          B is DOUBLE PRECISION array, dimension (N)
[out]WORK
          WORK is DOUBLE PRECISION array, dimension (2*N)
[out]INFO
          INFO is INTEGER
          = 0:  successful exit
          < 0: if INFO = -k, the k-th argument had an illegal value
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.