fortran

问题 Say I have a package already installed on my machine and I want to figure out if I need to regenerate the module include files ( .mod ) to make them compatible with the rest of my compilation. Is there any way to do this? 回答1: If the module is built using gfortran then using strings on the mod file (on Linux) will provide the compiler name and the version number. However, for Intel, the strings command will only show the compiler version number. 回答2: I had a similar problem at some point with

问题 I am using automatic allocation on assignment to calculate the difference of two arrays, with bounds starting at 0: program main implicit none integer, allocatable :: a(:), b(:), c(:) allocate(a(0:10)) allocate(b(0:10)) a = 1 b = 2 write (*,*) lbound(a) write (*,*) lbound(b) c = b - a write (*,*) lbound(c) end program main Both, gfortran and ifort give the output: 0 0 1 Why doesn't c have the same bounds as a and b? Is there a short and concise (without an explicit allocate) way of making

问题 I have function that returns an array, say function f(A) implicit none real, intent(in) :: A(5) real, intent(out) :: f(5) f = A+1 end My question is, how can I define f in the main program unit? E.g. program main implicit none real :: A(5) real, dimension(5), external :: f ! does not work ... end 回答1: You need an explicit interface. You can do this in a few ways. Explicitly in the scoping unit that calls f : interface function f(A) implicit none real, intent(in) :: A(5) real :: f(5) end

问题 I have function that returns an array, say function f(A) implicit none real, intent(in) :: A(5) real, intent(out) :: f(5) f = A+1 end My question is, how can I define f in the main program unit? E.g. program main implicit none real :: A(5) real, dimension(5), external :: f ! does not work ... end 回答1: You need an explicit interface. You can do this in a few ways. Explicitly in the scoping unit that calls f : interface function f(A) implicit none real, intent(in) :: A(5) real :: f(5) end

问题 I am learning Fortran, and I'm stuck trying to compile a module for later use. In the main program I have this, which asks for two numbers and then calls the function in the module: use exponentiate integer::a,b write *, 'A' read *, 'a write *, 'B' read *, 'b write *,expo(a,b) (I haven't tried that out because I need to compile the module first, but that's not the issue) Then, on another file I have this code, which (If I understood anything correctly) is just a standard module with a

问题 I have a 1-dimensional work array real(8), allocatable :: work(:) which is passed to a subroutine that operates on a 2-dimensional array pure subroutine f(work, dim1, dim2) real(8), intent(out) :: work(dim1, dim2) integer, intent(in) :: dim1, dim2 ... What is the difference in the following ways of passing the array? call f(work, dim1, dim2) call f(work(1), dim1, dim2) Are they the same in that they just pass the pointer to the first array element or is there some extra overhead with either

问题 I have a 1-dimensional work array real(8), allocatable :: work(:) which is passed to a subroutine that operates on a 2-dimensional array pure subroutine f(work, dim1, dim2) real(8), intent(out) :: work(dim1, dim2) integer, intent(in) :: dim1, dim2 ... What is the difference in the following ways of passing the array? call f(work, dim1, dim2) call f(work(1), dim1, dim2) Are they the same in that they just pass the pointer to the first array element or is there some extra overhead with either

问题 I am trying to do something basic, but I can't find the relevant information on how to compile. I tried the following without success: gfortran testintegral.f90 -lgsl -lgslcblas testintegral.f90:19.6: use fgsl 1 Fatal Error: Can't open module file 'fgsl.mod' for reading at (1): No such file The file is taken from http://de.wikibooks.org/wiki/Fortran:_FGSL#Beispiel:_Numerische_Integration (page in german but readily understandable) so I suppose it is OK. Maybe the syntax of the compilation

问题 The following implementation of Borwein’s algorithm with quartic convergence in Fortran admittedly calculates Pi, but converges simply too fast. In theory, a converges quartically to 1/π. On each iteration, the number of correct digits is therefore quadrupled. ! pi.f90 program main use, intrinsic :: iso_fortran_env, only: real128 implicit none real(kind=real128), parameter :: CONST_PI = acos(-1._real128) real(kind=real128) :: pi integer :: i do i = 1, 10 pi = borwein(i) print '("Pi (n = ", i3

问题 I am trying to do something basic, but I can't find the relevant information on how to compile. I tried the following without success: gfortran testintegral.f90 -lgsl -lgslcblas testintegral.f90:19.6: use fgsl 1 Fatal Error: Can't open module file 'fgsl.mod' for reading at (1): No such file The file is taken from http://de.wikibooks.org/wiki/Fortran:_FGSL#Beispiel:_Numerische_Integration (page in german but readily understandable) so I suppose it is OK. Maybe the syntax of the compilation