Program f08anfe ! F08ANF Example Program Text ! Mark 24 Release. NAG Copyright 2012. ! .. Use Statements .. Use nag_library, Only: dznrm2, nag_wp, zgels ! .. Implicit None Statement .. Implicit None ! .. Parameters .. Integer, Parameter :: nb = 64, nin = 5, nout = 6 ! .. Local Scalars .. Real (Kind=nag_wp) :: rnorm Integer :: i, info, lda, lwork, m, n ! .. Local Arrays .. Complex (Kind=nag_wp), Allocatable :: a(:,:), b(:), work(:) ! .. Executable Statements .. Write (nout,*) 'F08ANF Example Program Results' Write (nout,*) ! Skip heading in data file Read (nin,*) Read (nin,*) m, n lda = m lwork = n + nb*m Allocate (a(lda,n),b(m),work(lwork)) ! Read A and B from data file Read (nin,*)(a(i,1:n),i=1,m) Read (nin,*) b(1:m) ! Solve the least squares problem min( norm2(b - Ax) ) for x ! The NAG name equivalent of zgels is f08anf Call zgels('No transpose',m,n,1,a,lda,b,m,work,lwork,info) ! Print solution Write (nout,*) 'Least squares solution' Write (nout,99999) b(1:n) ! Compute and print estimate of the square root of the residual ! sum of squares ! The NAG name equivalent of dznrm2 is f06jjf rnorm = dznrm2(m-n,b(n+1),1) Write (nout,*) Write (nout,*) 'Square root of the residual sum of squares' Write (nout,99998) rnorm 99999 Format (4(' (',F7.4,',',F7.4,')':)) 99998 Format (1X,1P,E10.2) End Program f08anfe