計算ルーチン: 複素三角連立１次方程式の解 : (多重右辺)

ZTPTRS Example Program Data
  4  2                                                    :Values of N and NRHS
  'L'                                                     :Value of UPLO
 ( 4.78, 4.56)
 ( 2.00,-0.30) (-4.11, 1.25)
 ( 2.89,-1.34) ( 2.36,-4.25) ( 4.15, 0.80)
 (-1.89, 1.15) ( 0.04,-3.69) (-0.02, 0.46) ( 0.33,-0.26)  :End of matrix A
 (-14.78,-32.36) (-18.02, 28.46)
 (  2.98, -2.14) ( 14.22, 15.42)
 (-20.96, 17.06) (  5.62, 35.89)
 (  9.54,  9.91) (-16.46, -1.73)                          :End of matrix B

 ZTPTRS Example Program Results

 Solution(s)
                    1                 2
 1  (-5.0000,-2.0000) ( 1.0000, 5.0000)
 2  (-3.0000,-1.0000) (-2.0000,-2.0000)
 3  ( 2.0000, 1.0000) ( 3.0000, 4.0000)
 4  ( 4.0000, 3.0000) ( 4.0000,-3.0000)

    Program ztptrs_example

!     ZTPTRS Example Program Text

!     Copyright 2017, Numerical Algorithms Group Ltd. http://www.nag.com

!     .. Use Statements ..
      Use lapack_example_aux, Only: nagf_file_print_matrix_complex_gen_comp
      Use lapack_interfaces, Only: ztptrs
      Use lapack_precision, Only: dp
!     .. Implicit None Statement ..
      Implicit None
!     .. Parameters ..
      Integer, Parameter :: nin = 5, nout = 6
      Character (1), Parameter :: diag = 'N', trans = 'N'
!     .. Local Scalars ..
      Integer :: i, ifail, info, j, ldb, n, nrhs
      Character (1) :: uplo
!     .. Local Arrays ..
      Complex (Kind=dp), Allocatable :: ap(:), b(:, :)
      Character (1) :: clabs(1), rlabs(1)
!     .. Executable Statements ..
      Write (nout, *) 'ZTPTRS Example Program Results'
!     Skip heading in data file
      Read (nin, *)
      Read (nin, *) n, nrhs
      ldb = n
      Allocate (ap(n*(n+1)/2), b(ldb,nrhs))

!     Read A and B from data file

      Read (nin, *) uplo
      If (uplo=='U') Then
        Read (nin, *)((ap(i+j*(j-1)/2),j=i,n), i=1, n)
      Else If (uplo=='L') Then
        Read (nin, *)((ap(i+(2*n-j)*(j-1)/2),j=1,i), i=1, n)
      End If
      Read (nin, *)(b(i,1:nrhs), i=1, n)

!     Compute solution
      Call ztptrs(uplo, trans, diag, n, nrhs, ap, b, ldb, info)

!     Print solution

      Write (nout, *)
      Flush (nout)
      If (info==0) Then

!       ifail: behaviour on error exit
!              =0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft
        ifail = 0
        Call nagf_file_print_matrix_complex_gen_comp('General', ' ', n, nrhs, &
          b, ldb, 'Bracketed', 'F7.4', 'Solution(s)', 'Integer', rlabs, &
          'Integer', clabs, 80, 0, ifail)

      Else
        Write (nout, *) 'A is singular'
      End If

    End Program