For the sake of future visitors, I suppose I’ll answer this even though it’s all answered in the comments above. As far as I’m aware, if your program is behaving properly, you cannot change the value of that parameter (“count”) in a call to MPI_Recv. Your argument status is too small, it should be an … Read more
I don’t think that there is some rationale behind such behavior. But as far as I know, Stefano, you used wrong terminology. In your code there is no assignment statement only variable (var) initialization using initialization expression (0). integer :: var = 0 ! type declaration & initialization integer :: var ! type declaration var … Read more
Read the binary file content like this: with open(fileName, mode=”rb”) as file: # b is important -> binary fileContent = file.read() then “unpack” binary data using struct.unpack: The start bytes: struct.unpack(“iiiii”, fileContent[:20]) The body: ignore the heading bytes and the trailing byte (= 24); The remaining part forms the body, to know the number of … Read more
You cannot make similar tricks with functions in Fortran directly. You also cannot return a closure in Fortran. Just write a wrapper. function wrap_f(x) result(res) … res = f(a,b,…) end function It can be an internal or module function and get a and b by the host association or it can use the module containing … Read more
A real which isn’t marked as double precision will be assumed to be single precision. Just because sometime later you assign it to a double precision variable, or convert it to double precision, that doesn’t mean that the value will ‘magically’ be double precision. It doesn’t look ahead to see how the value will be … Read more
Modules are always the right thing to use 😉 If you have a very simple F90 program you can include functions and subroutines in the ‘contains’ block: program simple implicit none integer :: x, y x = … y = myfunc(x) contains function myfunc(x) result(y) implicit none integer, intent(in) :: x integer :: y … … Read more
In Fortran 1/2 is an integer division operation which will round down to, in this case, 0. Same for 1/3. If you want a real result, do a real division operation, such as 1.0/2.0. Note that assigning the result of 1/2 to a real variable will set the real variable to 0.0, that is the … Read more
A link-time error like these messages can be for many of the same reasons as for more general uses of the linker, rather than just having compiled a Fortran program. Some of these are covered in the linked question about C++ linking and in another answer here: failing to specify the library, or providing them … Read more
For unformated IO, Fortran compilers typically write the length of the record at the beginning and end of the record. Most but not all compilers use four bytes. This aids in reading records, e.g., length at the end assists with a backspace operation. You can suppress this with the new Stream IO mode of Fortran … Read more