Why is My Fortran Code Not Working?

[Petar Mali]

I'm new in programing. Does enybody knows why this don't work.

implicit none
integer i,N,Ntot,istag
real*8 t,U,tpin,k,eg,mstag
real*8 rho,Umstag,Urho
real*8 eaf,eaftot,lambdaminus

write(6,*) 'N,Ntot,t,U'
read (5,*) N,Ntot,t,U
write(36,*) Ntot/2+1

tpin=8.d0*datan(1.do)/dfloat(N)
rho=dfloat(Ntot)/dfloat(N)
Urho=U*rho/2.do

do 1000 istag,Ntot,2

mstag=dfloat(istag)/dfloat(N)
Umstag=U*mstag/2.do

eaftot=0.do
do 200,i=-Ntot/4+1,Ntot/4
k=tpin*dfloat(i)
ek=-2.do*t*dcos(k)
lambdaminus=-dsqrt(ek*ek+Umstag*Umstag)
lambdaminus=lambdaminus+Urho
eaftot=eaftot+lambdaminus
200 continue
eaftot=2.do*eaftot/dfloat(N)-U*(rho*rho-mstag*mstag)/4.do

write(36,990)
990 format(i6,f16.6)

1000 continue
end

 

[jtbell]

Please define "this don't work". What is it supposed to do and what does it actually do? What error messages do you get, if any, and when? (when you try to compile the program, or when you try to run it?)

 

[AlephZero]

Your constants like 2.do should be 2.d0 (with a zero, not a letter o).

If that doesn't fix your problem ... what [STRIKE]Christo[/STRIKE] JT Bell said.

 

[Petar Mali]

Tnx. That was mistake.