NAG Library Manual, Mark 27.3
Interfaces:  FL   CL   CPP   AD 

NAG FL Interface Introduction
Example description
    Program g02cefe

!     G02CEF Example Program Text

!     Mark 27.3 Release. NAG Copyright 2021.

!     .. Use Statements ..
      Use nag_library, Only: g02cef, nag_wp, x04caf
!     .. Implicit None Statement ..
      Implicit None
!     .. Parameters ..
      Integer, Parameter               :: nin = 5, nout = 6
!     .. Local Scalars ..
      Integer                          :: i, ifail, ldr, ldr2, ldssp, ldssp2,  &
                                          m, n
      Character (80)                   :: fmt
!     .. Local Arrays ..
      Real (Kind=nag_wp), Allocatable  :: r(:,:), r2(:,:), ssp(:,:),           &
                                          ssp2(:,:), std(:), std2(:), xbar(:), &
                                          xbar2(:)
      Integer, Allocatable             :: korder(:)
!     .. Executable Statements ..
      Write (nout,*) 'G02CEF Example Program Results'
      Write (nout,*)

!     Skip heading in data file
      Read (nin,*)

!     Read in the problem size
      Read (nin,*) n, m

      ldr = n
      ldr2 = m
      ldssp = n
      ldssp2 = m
      Allocate (r(ldr,n),r2(ldr2,m),ssp(ldssp,n),ssp2(ldssp2,m),std(n),        &
        std2(m),xbar(n),xbar2(m),korder(m))

!     Read in the data
      Read (nin,*) xbar(1:n)
      Read (nin,*) std(1:n)
      Read (nin,*)(ssp(i,1:n),i=1,n)
      Read (nin,*)(r(i,1:n),i=1,n)

!     Read in the reordering vector
      Read (nin,*) korder(1:m)

!     Format for displaying vectors
      Write (fmt,99999) '(1x,a,', n, '(1x,f10.4))'

!     Display data
      Write (nout,fmt) 'Original vector XBAR :   ', xbar(1:n)
      Write (nout,*)
      Write (nout,fmt) 'Original vector STD  :   ', std(1:n)
      Write (nout,*)
      Flush (nout)
      ifail = 0
      Call x04caf('General',' ',n,n,ssp,ldssp,'Original matrix SSP  :',ifail)
      Write (nout,*)
      Flush (nout)
      ifail = 0
      Call x04caf('General',' ',n,n,r,ldr,'Original matrix R    :',ifail)
      Write (nout,*)

!     Calculate summaries on reduced number of variables
      ifail = 0
      Call g02cef(n,xbar,std,ssp,ldssp,r,ldr,m,korder,xbar2,std2,ssp2,ldssp2,  &
        r2,ldr2,ifail)

!     Display results
      Write (nout,fmt) 'New vector XBAR2 :   ', xbar2(1:m)
      Write (nout,*)
      Write (nout,fmt) 'New vector STD2  :   ', std2(1:m)
      Write (nout,*)
      Flush (nout)
      ifail = 0
      Call x04caf('General',' ',m,m,ssp2,ldssp2,'New matrix SSP2  :',ifail)
      Write (nout,*)
      Flush (nout)
      ifail = 0
      Call x04caf('General',' ',m,m,r2,ldr2,'New matrix R2    :',ifail)

99999 Format (A,I0,A)
    End Program g02cefe