I am pretty new to to fortran and I don't really know why am I getting this error.

```
integrand(i)=inte(x(i),beta,r2,r1)
1 Error: Unclassifiable statement at (1) calka11.f95:97.6:
```

I have made all the variables into a module file and then call them using

```
use
```

and when I am getting those variables into the code file again It works fluently again.

```
module zmienne
real(10) :: r, u, r6, tempred, f, r2, r1, calka,beta
real(10) :: inte
real :: start, finish
integer:: i
integer, parameter :: Ngauss = 8
real(10),dimension(ngauss),parameter::xx=(/-0.9602898565d0,&
-0.7966664774d0,-0.5255324099d0,-0.1834346425d0,&
0.1834346425d0,0.5255324099d0,0.7966664774d0,0.9602898565d0/)
real(10),Dimension(ngauss),parameter::ww=(/0.1012285363d0,&
0.2223810345d0,0.3137066459d0,0.3626837834d0,&
0.3626837834d0,0.3137066459d0,0.2223810345d0,0.1012285363d0/)
real(10),dimension(ngauss)::x,w,integrand
integer, parameter :: out_unit=1000
integer, parameter :: out_unit1=1001
integer, parameter :: out_unit2=1002, out_unit3=1003
real(10), parameter :: error=0.000001
real(10):: total_calka, division,tot_old,blad
real(10),parameter:: intrange=7.0
integer::j,irange
end module zmienne
```

The main program that uses the module:

```
program wykres
use zmienne
implicit none
open(unit=out_unit, file='wykresik.dat', action='write', status='replace')
open(unit=out_unit1, file='wykresik1.dat', action='write')
open(unit=out_unit2, file='wykresik2.dat', action='write')
open(out_unit3, file='wykresik3.dat', action='write')
! the gaussian points (xx) and weights (ww) are for the [-1,1] interval
! for [0,1] interval we have (vector instr.)
x=0.5d0*(xx+1.0d0)
w=0.5d0*ww
! plots
tempred = 1.0
beta=4.d0/tempred
call cpu_time(start)
do i=1,1000
r=float(i)*0.01
r6=(1.0/r)**6
u=beta*r6*(r6-1.0)
f=exp(-u/tempred)-1.0
write(out_unit,*) r, u
write(out_unit1,*)r, f
write(out_unit2,*)r, r*r*f
end do
call cpu_time(finish)
print '("Time = ",f6.3," seconds.")',finish-start
! end of plots
! integration 1
calka=0.0
r1=0.0
r2=0.5
do i=1,ngauss
r=(r2-r1)*x(i)+r1
r6=(1.0/r)**6
u=beta*r6*(r6-1.0d0)
! check for underflows
if (u>100.d0) then
f=-1.0d0
else
f=exp(-u)-1.d0
endif
! the array integrand is introduced in order to perform vector calculations below
integrand(i)=r*r*f
calka=calka+integrand(i)*w(i)
enddo
calka=calka*(r2-r1)
write(*,*)calka
! end of integration
! integration 2
calka=0.0
do i=1,ngauss
integrand(i)=inte(x(i),beta,r2,r1)
calka=calka+integrand(i)*w(i)
enddo
calka=calka*(r2-r1)
! end of integration 2
write(*,*)calka
! vector integration and analytical result
write(*,*)sum(integrand*w*(r2-r1)),-(0.5**3)/3.0
!**************************************************************
! tot_calka - the sum of integrals all integration ranges
! dividion the initial length of the integration intervals
! tot_old - we will compare the results fro two consecutive divisions.
! at the beginning we assume any big number
! blad - the difference between two consecutive integrations,
! at the beginning we assume any big number
! error - assumed precission, parameter, it is necassary for
! performing do-while loop
total_calka=0.0
division=0.5
tot_old=10000.0
blad=10000.0
do while (blad>error)
! intrange - the upper integration limit, it should be estimated
! analysing the plot of the Mayer function. Here - 7.
! irange = the number of subintegrals we have to calculate
irange=int(intrange/division)
total_calka=-(0.5**3)/3.0
! the analytical result for the integration range [0,0.5]
! the loop over all the intervals, for each of them we calculate
! lower and upper limits, r1 and r2
do j=1,irange
r1=0.5+(j-1)*division
r2=r1+division
calka=0.0
! the integral for a given interval
do i=1,ngauss
integrand(i)=inte(x(i),beta,r2,r1)
calka=calka+integrand(i)*w(i)
enddo
total_calka=total_calka+calka*(r2-r1)
enddo
! aux. output: number of subintervals, old and new integrals
write(*,*) irange,division,tot_old,total_calka
division=division/2.0
blad=abs(tot_old-total_calka)
tot_old=total_calka
! and the final error
write(*,*) blad
enddo
open(1,file='calka.dat', access='append')
! the secod viarial coefficient=CONSTANT*total_calka,
! CONSTANT is omitted here
write(1,*)tempred,total_calka
close(1)
end program wykres
```

I also made the external to this real function and it gives me an error for every variable in the module. It looks like that for example

```
undefined reference to `__zmienne_MOD_total_calka'
```

Inte is a real defined variable, which is necessary for me to calculate this integral.

```
integrand(i)=inte(x(i),beta,r2,r1)
```

Why it doesn't work when it's in another file, while it was working while its been inside it. That's weird

This is the original code:

```
program wykres
implicit none
real(10) :: r, u, r6, tempred, f, r2, r1, calka,beta
! beta - an auxiliary variable
real(10) :: inte
! inte - the function defined below
real :: start, finish
integer:: i
integer, parameter :: Ngauss = 8
real(10),dimension(ngauss),parameter::xx=(/-0.9602898565d0,&
-0.7966664774d0,-0.5255324099d0,-0.1834346425d0,&
0.1834346425d0,0.5255324099d0,0.7966664774d0,0.9602898565d0/)
real(10),Dimension(ngauss),parameter::ww=(/0.1012285363d0,&
0.2223810345d0,0.3137066459d0,0.3626837834d0,&
0.3626837834d0,0.3137066459d0,0.2223810345d0,0.1012285363d0/)
real(10),dimension(ngauss)::x,w,integrand
integer, parameter :: out_unit=1000
integer, parameter :: out_unit1=1001
integer, parameter :: out_unit2=1002, out_unit3=1003
real(10), parameter :: error=0.000001
real(10):: total_calka, division,tot_old,blad
real(10),parameter:: intrange=7.0
integer::j,irange
open(unit=out_unit, file='wykresik.dat', action='write', status='replace')
open(unit=out_unit1, file='wykresik1.dat', action='write')
open(unit=out_unit2, file='wykresik2.dat', action='write')
open(out_unit3, file='wykresik3.dat', action='write')
! the gaussian points (xx) and weights (ww) are for the [-1,1] interval
! for [0,1] interval we have (vector instr.)
x=0.5d0*(xx+1.0d0)
w=0.5d0*ww
! plots
tempred = 1.0
call cpu_time(start)
do i=1,1000
r=float(i)*0.01
r6=(1.0/r)**6
u=4.0d0*r6*(r6-1.0)
f=exp(-u/tempred)-1.0
write(out_unit,*) r, u
write(out_unit1,*)r, f
write(out_unit2,*)r, r*r*f
end do
call cpu_time(finish)
print '("Time = ",f6.3," seconds.")',finish-start
! end of plots
! integration 1
calka=0.0
r1=0.0
r2=0.5
! auxiliary variable
beta=4.d0/tempred
do i=1,ngauss
r=(r2-r1)*x(i)+r1
r6=(1.0/r)**6
u=beta*r6*(r6-1.0d0)
! check for underflows
if (u>100.d0) then
f=-1.0d0
else
f=exp(-u)-1.d0
endif
! the array integrand is introduced in order to perform vector calculations below
integrand(i)=r*r*f
calka=calka+integrand(i)*w(i)
enddo
calka=calka*(r2-r1)
write(*,*)calka
! end of integration
! integration 2
calka=0.0
do i=1,ngauss
integrand(i)=inte(x(i),beta,r2,r1)
calka=calka+integrand(i)*w(i)
enddo
calka=calka*(r2-r1)
! end of integration 2
write(*,*)calka
! vector integration and analytical result
write(*,*)sum(integrand*w*(r2-r1)),-(0.5**3)/3.0
!**************************************************************
! tot_calka - the sum of integrals all integration ranges
! dividion the initial length of the integration intervals
! tot_old - we will compare the results fro two consecutive divisions.
! at the beginning we assume any big number
! blad - the difference between two consecutive integrations,
! at the beginning we assume any big number
! error - assumed precission, parameter, it is necassary for
! performing do-while loop
total_calka=0.0
division=0.5
tot_old=10000.0
blad=10000.0
do while (blad>error)
! intrange - the upper integration limit, it should be estimated
! analysing the plot of the Mayer function. Here - 7.
! irange = the number of subintegrals we have to calculate
irange=int(intrange/division)
total_calka=-(0.5**3)/3.0
! the analytical result for the integration range [0,0.5]
! the loop over all the intervals, for each of them we calculate
! lower and upper limits, r1 and r2
do j=1,irange
r1=0.5+(j-1)*division
r2=r1+division
calka=0.0
! the integral for a given interval
do i=1,ngauss
integrand(i)=inte(x(i),beta,r2,r1)
calka=calka+integrand(i)*w(i)
enddo
total_calka=total_calka+calka*(r2-r1)
enddo
! aux. output: number of subintervals, old and new integrals
write(*,*) irange,division,tot_old,total_calka
division=division/2.0
blad=abs(tot_old-total_calka)
tot_old=total_calka
! and the final error
write(*,*) blad
enddo
open(1,file='calka.dat', access='append')
! the secod viarial coefficient=CONSTANT*total_calka,
! CONSTANT is omitted here
write(1,*)tempred,total_calka
close(1)
end program wykres
```

Jesus christ, there were a code below the end program... Thread may be closed now. Thank you to everyone.

```
real(kind=10) function inte(y,beta,r2,r1)
implicit none
real(kind=10)::r,beta,r6,r2,r1,u,y
r=(r2-r1)*y+r1
r6=(1.0/r)**6
u=beta*r6*(r6-1.0d0)
if (u>100.d0) then
inte=-1.0d0
else
inte=exp(-u)-1.d0
endif
inte=r*r*inte
end
```