allocatable arrays problem!

[milenko76]

I got this:
Subscript #2 of the array X has value 3 which is greater than the upper bound of 2
How to set up bounds?

integer :: i,j,k,c,n,a
real,dimension,,allocatable :: x
Then comes main program:
read(10,*)n,c
a=n*c
allocate(x(n,c))
Reads 4,2 but latter values of array elements will be greater then 2.
How to solve this?

 

[mikrom]

Don't understand what you want. If you allocate x(4, 2) you cannot later use x,3). I think you didn't post the relevant part of the code.

 

[milenko76]

program pr7
use def
use face
implicit none
real :: func
open(10,file='pch.dat',status='old')
open(11,file='cl.dat',status='old')
open(12,file='lj.dat',status='old')
open(14,file='b.dat',status='old')

read(10,*)n,c
a=n*c

allocate(x(n,c))
allocate(pp(a))

do i=1,n
read(11,*)(x(i,j),j=1,c)
end do

read(12,*)(pp(j),j=1,a)

allocate(work_s(a))
allocate(work_p(a))

write(*,*)x
write(*,*)pp
write(*,*)work_s
func=getvalue(pp)
write(*,*)func

deallocate(x)
deallocate(pp)
deallocate(work_s)
deallocate(work_p)
end program

function getvalue(vector)
use def
implicit none
real(kind(1d0)) getvalue
real(kind(1d0)) row_sum, total
real,dimension(n,c) :: vv
real,dimension), pointer:: vector
real,dimension), pointer :: dist_ik
vv = reshape(vector, (/ n,c /))
vector => work_p
dist_ik => work_s
total = 0d0
row_sum = 0d0
do i = 1, n
dist_ik = vv(i,-x(i,
row_sum = 1.0/dot_product(dist_ik, dist_ik) + row_sum
end do
total = 1d0/row_sum + total
getvalue= total
end function
So the problem is HERE:dist_ik = vv(i,-x(i,,but how?

 

[mikrom]

What you posted doesn't work for me. I get an error:

  func=getvalue(pp)
               1
Error: Actual argument for 'vector' must be a pointer at (1)

To get it work I used this:

  ptr_pp => pp
  func=getvalue(ptr_pp)

where the variable declarations are:

   real, dimension(:), allocatable, target :: pp
   real, dimension(:), pointer::  ptr_pp

The other problem is, how you compute dist_ik:

do i = 1, n
  dist_ik = vv(i,:) - x(i,:)
end do

When you have for example n=4 and c=2, then your matrices have dimension 4 x 2 and your array dist_ik has dimension 4*2=8.
So because the matrices have 2 columns, then the substraction above computes every time only the first 2 elements of dist_ik and other 6 elements contain junk (because you did not initialize dist_ik). Then when you compute the dot product of dist_ik (which contains junk data) you get junk result.

To demonstrate it - consider, I have:

 X=
 1. 5.
 2. 6.
 3. 7.
 4. 8.

 PP=
 10.
 10.
 10.
 10.
 10.
 10.
 10.
 10.

Then I get

 VV=
 10. 10.
 10. 10.
 10. 10.
 10. 10.

and the loop inside of the function

    do i = 1, n
      dist_ik = vv(i,:) - x(i,:)
      ...
    end do

delivers for example this:

 for i=1:
 DIST_IK=
 9.
 5.
 -9.1749E-41
 6.337112E-10
 -9.999255
 3.3926558E+27
 9.40217E-39
 1.3790198E+11

 for i=2:
 DIST_IK=
 8.
 4.
 9.458795E-39
 1.7657385E+22
 7.8996415E+34
 -10.
 816213.1
 8.442228E+8

 for i=3:
 DIST_IK=
 7.
 3.
 -1.1905E-41
 1.8176815E+31
 -10.
 -10.
 5.8524984E+7
 12.773255

 for i=4:
 DIST_IK=
 6.
 2.
 -1.2208E-41
 2.2869996E+14
 7.185757E+28
 7.6830766E+31
 0.048658613
 893.11414

IMHO, how you compute is wrong.

 

[milenko76]

No,it gives me the same message again.The code now:
program pr7
use def
implicit none
real :: func
real(kind(1d0)) getvalue
open(10,file='pch.dat',status='old')
open(11,file='cl.dat',status='old')
open(12,file='lj.dat',status='old')
open(14,file='b.dat',status='old')
read(10,*)n,c
a=n*c

allocate(x(n,c))
allocate(pp(a))

do i=1,n
read(11,*)(x(i,j),j=1,c)
end do

read(12,*)(pp(j),j=1,a)

allocate(work_s(a))
allocate(work_p(a))

ptr_pp => pp
func=getvalue(ptr_pp)
write(*,*)func

deallocate(x)
deallocate(pp)
deallocate(work_s)
deallocate(work_p)
end program

function getvalue(vector)
use def
implicit none
real(kind(1d0)) getvalue
real(kind(1d0)) row_sum, total
real,dimension(n,c) :: vv
real,dimension), pointer :: vector
real,dimension), pointer :: dist_ik
vv = reshape(vector, (/ n,c /))
vector => work_p
dist_ik => work_s
total = 0d0
do k=1,n
row_sum = 0d0
do i = 1, c
dist_ik = vv(i,-x(i,
row_sum = 1.0/dot_product(dist_ik, dist_ik) + row_sum
end do
total = 1d0/row_sum + total
end do
getvalue= total
end function getvalue

 

[milenko76]

module def

implicit none

integer :: i,j,k,a,n,c
real, dimension), allocatable, target :: work_s
real, dimension), allocatable, target :: work_p
real, dimension), allocatable, target :: pp
real, dimension), pointer:: ptr_pp
real, dimension,, allocatable :: x

end module

 

[milenko76]

I have manage to solve the problem,mikrom you were right it was issue of initialiasing dist_ik.

 

[mikrom]

The quick workaround with minimal code changes could be something like this:

do i = 1, n
  dist_ik = vv(i,:) - x(i,:)
  ! correction: initialize all elements from c+1 which contain junk
  dist_ik(c+1:) = 0
  ...
end do