On macOS Big Sur v11.1: Relevant SO post: https://apple.stackexchange.com/questions/408999/gfortran-compiler-error-on-mac-os-big-sur The fix is to add the stdlib to your $LIBRARY_PATH. For some reason or another it isn’t in your standard $PATH anymore on 11.1. export LIBRARY_PATH=”$LIBRARY_PATH:/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/lib” (or add it to login file and restart terminal).
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
cpu_time() takes the time on the CPU, not the walltime. In parallel applications these are not the same. See here for details. Using system_clock() solves this problem: PROGRAM MAIN use omp_lib implicit none REAL*8 Times1,Times2 INTEGER I,J, iTimes1,iTimes2, rate real, allocatable, dimension(:) :: a allocate(a(1000)) CALL system_clock(count_rate=rate) DO J = 1, 1000 a(j)=j ENDDO ! … Read more
Fortran does not have templates, but you can put the code common to the functions handling different types in an include file as a kludge to simulate templates, as shown in this code: ! file “cumul.inc” ! function cumul(xx) result(yy) ! return in yy(:) the cumulative sum of xx(:) ! type, intent(in) :: xx(:) ! … Read more
Yes and no. First the no: Proper arrays in Fortran, such as those declared like this: integer, dimension(3,3,4) :: an_array or like this integer, dimension(:,:,:,:), allocatable :: an_array are regular; for each dimension there is only one extent. But, if you want to define your own type for a ragged array you can, and it’s … Read more
If a procedure has a dummy argument that is an allocatable, then an explicit interface is required in any calling scope. (There are numerous things that require an explicit interface, an allocatable dummy is but one.) You can provide that explicit interface yourself by putting an interface block for your subroutine inside the main program. … Read more
The following a literal Fortran translation of this answer. I had thought this was unnecessary, but the multiple differences in array indexing and memory layout might mean that it is worth doing a Fortran version. Let me start by saying that you generally don’t really want to do this – scatter and gather huge chunks … Read more
List-directed IO, i.e, write (*, *) is meant as a convenience. There are no settings to change its behavior. Different compilers will produce different output. Instead you can, as you have identified, use formatted IO. In this case you can use I0 as the format, which will produce the required number of digits, while I1 … Read more
As Alexander Vogt says, interface blocks can be useful for providing generic identifiers and allowing certain compiler checks. If you’re using interface blocks to create generic identifiers you’re probably doing so within modules, so the main reason to write such blocks when modules aren’t about is for the explicit interfaces that they create in the … Read more