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POFortran PRESENT() function with assumed length array crashes EDITED
 

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  1. POFortran PRESENT() function with assumed length array crashes EDITED
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    <p>i am completely lost.</p> <p>I try to pass two optional arguments to a function in fortran, and those two are arrays of an unknown length. The code compiles fine, but when the program run, it crashes during the evaluation of the PRESENT(arg) function. There is no error message in the command line, instead just the windows error notification pops up, and tells me "main.exe has stopped working" Any ideas on how to solve this?</p> <p>Here is the code, I deleted everything that is not necessary.</p> <pre><code>MODULE types ! Underlying data types: Bra, Ket, and Oper type bra complex*8, dimension(:,:), allocatable :: dat integer*4 :: typ ! = "Bra" integer*4, dimension(2) :: dims end type bra type ket complex*8, dimension(:,:), allocatable :: dat integer*4 :: typ ! = "Ket" integer*4, dimension(2) :: dims end type ket type oper complex*8, dimension(:,:), allocatable :: dat integer*4 :: typ ! = "Operator" integer*4, dimension(2) :: dims end type oper END MODULE types MODULE basics ! The types are declared in an extra module, to be imported here ! Otherwise it is not possible to use derived types in procedures use types interface operator (*) ! "Quantum" multiplication procedure otk ! Operator Times Ket O *|B &gt; = |C&gt; end interface CONTAINS ! Fock state function fock(N,M) ! N is the dimension of the underlying array ! M is the number of photons inside ! M=1 is vacuum integer*4 :: N,M type(ket) :: fock ! Check is the passed dimensions are okay if (N&lt;2 .or. M&lt;0 .or. M &gt; N-1) then print*,'Invalid input while making a fock state' print*,'N=',N,'M=',M stop end if ! Allocate and initilaize with zeros allocate(fock%dat(N,1)) fock%dat = (0d0,0d0) ! Now actually make the state by replacing a zero with 1 fock%dat(M+1,1) = (1d0,0d0) ! Set type of the object to 'ket' fock%typ = 2 ! Set the dimensions fock%dims = [N,1] end function fock ! Identity matrix function qeye(N) integer*4 :: N,i type(oper) :: qeye ! Allocate and initilaize with zeros allocate(qeye%dat(N,N)) qeye%dat = (0d0,0d0) ! Set diagonal elements to 1 do i = 1,N qeye%dat(i,i) = (1d0,0d0) end do ! Set type of the object to 'oper' qeye%typ = 4 ! Set the dimensions qeye%dims = [N,N] end function qeye ! Operator Times Ket function otk(left, right) type(oper), intent(in) :: left type(ket), intent(in) :: right type(ket) :: otk ! If the operator is as wide, as the state is high, do matrix multiplication if (left%dims(2) == right%dims(1)) then ! Result is a Ket vector again allocate(otk%dat(left%dims(1),1)) otk%dat = matmul(left%dat,right%dat) ! Also set data type and dimensions of the result otk%dims = [right%dims(1),1] otk%typ = 2 return else print*,'You are trying to use an operator on a ket of inconsistent dimensions' print*,left%dims,'and',right%dims stop end if end function otk end module basics MODULE RK ! Import modules to work with quantum objects use types use basics contains subroutine rungekutta(state,HAM,times,results) ! In-/Output: ! Starting state, also final state type(ket) :: state ! Function delivering time dependent hamiltonian type(oper), external :: HAM ! Array with times at which to do calculations real*8, dimension(:) :: times ! Placeholder for the length of a given time step real*8 :: t_0, t_step ! Optional array of ket states to hold all the intermediate results type(ket), dimension(:),optional :: results ! Variables for internal calculations type(ket) :: psi0 ! Looping coefficients integer*8 :: ii ! Start of the calculations ! (The actual Runge-Kutta method is different, but not needed now) results(1) = state do ii = 1, size(times)-1 t_0 = times(ii) t_step = times(ii+1) - times(ii) psi0 = results(ii) results(ii+1) = HAM(t_0) * psi0 end do ! Save the last calculated state to the input/output variable state = results(size(results)) end subroutine rungekutta end MODULE RK module dummy ! Import modules to work with quantum objects use types use basics CONTAINS ! Define Hamiltonian function function testHAM(t, freqs, coefs) type(oper) :: testHAM real*8 :: t ! Optional variables is the Hamiltonian is time dependent real*8, dimension(:), optional :: freqs, coefs testHAM = qeye(2) ! Variable part if (.NOT.present(freqs)) then print*,'gotcha' end if end function testHAM end module dummy program main ! Import modules to work with quantum objects use types use basics use RK ! Import hamilton definition use dummy IMPLICIT NONE ! Define variables type(ket) :: start, goal real*8, dimension(:), allocatable :: timesarr integer*4 :: N,i,M,j,k,l,mm type(ket), dimension(:), allocatable :: results ! Set number of steps, and the total time N = 5000 allocate(timesarr(N)) timesarr = [0d0,1d0] start=fock(2,0) ! Allocate the vector holding the results allocate(results(N)) results = start call rungekutta(start,testHAM,timesarr,results) end program main </code></pre> <p>I am using the optional keyword also with the "results" array, and somewhere else, and it works fine. I would really appreciate any help, because I am really not in the mood to wrok around that stuff, because it would make the code even more messy :)</p> <p>Thanks in advance!</p>
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    1. USMaxim Moloshenko
    1. USMaxim Moloshenko
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      1. POFortran PRESENT() function with assumed length array crashes EDITED
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    1. COThe main program is really just there to show you how I pass the arguments, or actually, not pass. I am pretty sure the problem is somewhere in the function.
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      1. POFortran PRESENT() function with assumed length array crashes EDITED
      1. USMaxim Moloshenko
    2. COI don't think anyone is going to be able to help you because you didn't include `types`, `basic` and `RK` in the above. Do you understand the idea of minimum **working** example?
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      1. POFortran PRESENT() function with assumed length array crashes EDITED
      1. USKyle Kanos
    3. CONor did you include the actual error you are getting. Please update with both a *compilable* example that produces the error **and** the associated error.
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      1. POFortran PRESENT() function with assumed length array crashes EDITED
      1. USKyle Kanos
 

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