invalid character at name 1

Question

Trying to learn Fortran for a project. In a very simple program I am getting invalid character error.

program foo
   implicit none    
   integer :: n_samp
   integer :: samp_len
   integer :: x_len
   integer :: y_len
   n_samp=2
   samp_len=2
   y_len=11
   x_len=2
   real(8),dimension(n_samp,samp_len,y_len,x_len)=Yvec
end program foo

error generated by GFORTRAN

t.f90:11.12:

real(8), dimension(n_samp,samp_len,y_len,x_len)=Yvec
       1

Error: Invalid character in name at (1)

What is the cause of this error?

score 2 · Accepted Answer · edited May 23 '17 at 11:58

2

The correct syntax is

real(8), dimension(n_samp,samp_len,y_len,x_len) :: Yvec

The :: is obligatory when specifying any attributes (as the dimension in your case).

As @AlexanderVoigt points out, all variable declaration must be placed in the declaration part of the code, i.e., at the beginning.

I do not recommend using real(8) because that is not well defined, the 8 can mean anything, it is an index to a table of kinds and different compilers can have something different at place 8 in that table. See Fortran 90 kind parameter

edited May 23 '17 at 11:58

Community

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answered Apr 28 '15 at 08:38

Vladimir F Героям слава

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Also, declarations mustn't be in the main body! – Alexander Vogt Apr 28 '15 at 08:41
Correct, I missed the previous lines. – Vladimir F Героям слава Apr 28 '15 at 08:41
Mhm... Maybe we should merge our posts! – Alexander Vogt Apr 28 '15 at 08:42
Aah! double colon, so silly mistake from me. Xtremely sorry for troubling u guys.Thanks @vladimir F – pauli Apr 28 '15 at 08:46
Which way you mean? In high traffic tags it is common to have more answers, I think we can keep it. The priority of noticing the correct order is yours, of course. – Vladimir F Героям слава Apr 28 '15 at 08:46
@ashwinids Also the order of the statements, see Alexanders' answer. Nothing to be sorry about, everyone was a beginner once. – Vladimir F Героям слава Apr 28 '15 at 08:47
@VladimirF OK then, let's keep it. – Alexander Vogt Apr 28 '15 at 08:51

score 2 · Answer 2 · answered Apr 28 '15 at 08:39

2

That's simple: You are not allowed to have declarations in the main body (that is after some instructions)! Instead, you should use parameters:

program foo
   implicit none    
   integer,parameter :: n_samp=2
   integer,parameter :: samp_len=2
   integer,parameter :: x_len=11
   integer,parameter :: y_len=2
   real(8),dimension(n_samp,samp_len,y_len,x_len) :: Yvec ! Add. typo here
end program foo

answered Apr 28 '15 at 08:39

Alexander Vogt

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@ alexander in my actual code i'm using the declarations as u have defined. Thanks for the input. – pauli Apr 28 '15 at 09:04

invalid character at name 1

2 Answers2