Programming :: Fortran - Array-valued Function Leads To Segfault?
Jun 8, 2010
I'm trying to implement a solver for a system of differential equations in Fortran. The solver contains a number of functions which are supposed take real values, 1D arrays of real values or both as arguments and return arrays of real numbers, all of which cause the program to segfault. Example:
Code:
function y_exakt(t)
implicit none
real::t, pi
[code]....
(the last number in the array seems to change randomly). Then the program crashes either when f(t,y) is called or when dy is returned (after removing the call to f). What could cause these (memory?) problems and/or what could I do to identify the problem? Increasing the maximum stack size with ulimit or compiling the program with -fno-automatic has had no effect. I'm using gfortran (gcc 4.4.3) on a 64-bit Ubuntu Lucid machine. The complete program can be found at [URL].
I looked on the net for such function or example and didin't find anything, thus after having made one i guess it would be legitimate to drop it to see what others thinks of it.
#!/bin/bash addelementtoarray() { local arrayname=$1
I have two arrays of data, called data1.dat and data2.dat. each contains 60 data. What I want to do is to compare the data in each file and write the counting into bins. It goes like this. First, take the first data in data1.dat file and compare with the 60 data in data2.dat file. If there is any data which is same with the data in data1.dat then it count in bin. The total bins are also 60. Next it goes to the second data in data1.dat and compare with all the 60 data in data2.dat. If there is any data same then it add in second bin. And it repeats to all the data in data1.dat
I (my friend) have a fortran program with the code along the following lines:
Code:
SUBROUTINE NY REAL, DIMENSION(4000,4000) :: a, b, c ... RETURN END SUBROUTINE PARAMETERS
The problem is that the huge matrices are retained in memory even after the subroutine ends. Is there an easy way to declare the arrays in a sort of dynamic way, like they were in the following C example?
Code:
void ny(void) { double a[4000,4000]; ... }
I mean in the C example the memory is released as soon ny() exits.
I have a new problem; i want to call a subroutine's fortran which have a function in the argument and the compilation ran properly, but when i execute the program this shows me an "Segmentation fault". This is my c++ program:
$1 is an argument which is actually and array. In function we want to assign a value 0 of it's first content. But it's wrong way. Anybody know the right way to assign value in function by passing as argument.
I am trying to pass an array to thread program. Its printing the val[0] value but its not printing value at val[1]. Can somebody help me with this problem.
Alright, so I have been trying to resolve this issue for awhile, but now feel like help is very necessary.I have a 128(by)128(by)128 array in a MAT file, and am using the following MATLAB script to convert it to a DAT file:
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When I run gdb, it shows me the following: Code: (gdb) run b2-n00.ini Starting program: sv_node b2-n00.ini servant:12600> [New LWP 1] [New LWP 2] [New LWP 3] [New LWP 4] [New LWP 5] [New LWP 6] Before Exiting[LWP 1 exited] procfs: fetch_registers, get_gregs line 3768, /proc/23952/lwp/1: No such file or directory.
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I'm trying to call some Fortran 95 code in C, but I'm having problems with integers not having the same value in C as in Fortran, and changing values upon each run of the program. I think it has to do with the integer type, but I don't know how to fix it. I'm running Gentoo x86. Here are the files I've got:
There are examples everywhere about calling f77 subroutine from IDL, but I have not found any material about IDL calling fortran written in f90 way(free style). I tried the following example, but write the subroutines in free style. When I run the makefile, it gives an error 'undefined reference to main_'.
Code:
SUBROUTINE SUM_ARRAY(argc, argv) !Called by IDL INTEGER*4 argc, argv(*) !Argc and Argv are integers j = LOC(argc) !Obtains the number of arguments (argc)
I want to call a subroutine in Fortran 90 from a c++ code. I can do it, when the fortran code have no module. But i need to call the subroutine in a fortran code that have an module. I have a simple program that shows my problem. The Fortran code is:
collect2: ld returned 1 exit status I Dont know where is the problem. Maybe it is in the call of the function. I found that the syntax have this form: extern void __namemodule__NMOD_namesubrutine(arg)
I'm not a Fortran coder but I need to call the sub-routine ADAPT.f from a c code.This subroutine calculates a multiple integral of a given function.My problem is that the c code works with no problem in a 32 bit machine but it does not in a 64 bit machine, and the problem seems to be related to adapt, which calculations gives a NA rather than the result of integration.Since fortran is quite obscure for me, I don't know why is this happening. Maybe I should change some data type (from real to double), but I'm not sure. Does anyone have a clue?
I have a 50 file name NSSAVE0001.vtk to NSSAVE0050.vtk.Do I have to manually type individually command to open each file or can I have a loop to open file?
I have a program which reads some parameters in from an input file before solving a differential equation. This program compiles fine, I'm using Numerical Algorithms Group (NAG) libraries to solve the differential equation so I'm also the NAG compiler called nagfor.
The namelist I have is declared as follows:
And the input file is:
When I run the code I get the following error message:
I really can't see what's wrong with this code.
Also, I'm using Fedora 11, and running the code in tcsh if this is relevant.
(I am using vector() and matrix() functions from "Numerical recipes in C".)There are 100 numbers to be stored in 2D array of 10 rows and 10 columns.100 numbers are stored in a 1D array.I get "segmentation fault" at the line indicated in the segment of my code below:
I am dealing with one FORTRAN 90 code, have made small changes.
milenko@milenkons:~/mt4$ make mt4 make: 'mt4' is up to date. milenko@milenkons:~/mt4$ ifort -c MT2DDIB1.FOR milenko@milenkons:~/mt4$ make mt4 make: 'mt4' is up to date. milenko@milenkons:~/mt4$ make mt4 make: 'mt4' is up to date. milenko@milenkons:~/mt4$ make mt4 make: 'mt4' is up to date.
I go for make command but it does not see that the source code has been modified.Than I do compilation from command line,try make again but no use. F95=ifort FFLAFGS= -O1
I am trying to write a loop to open four main-data-files. At each open of the main-data-file, I want the loop to open another four sub-files and split the data from the mail-data-file according to the creteria and dump into the four files. When the loop goes to the second main-data-file, it shall generate another 4 sub-files with different file name. And the process goes on. That means I will have total of 16 sub files for the four main-data-files. Each four files from the 16 files shall have specific name on it. Based on the code which I given below, I would say when the file at UNIT=100 is opened, 4 new files needed to be opened as well. They are:
i am graduate student and my X colleague gave me this Fortran 77 program to run my result files with. She is no longer reachable. I compiled the following program with gfortran, it compiled well but, when i run it, gave me end of file error. My output file (which is the input file for this program (DFILE1) ) has about 78,000 lines of velocities of atoms (Vx, Vy, Vz with 1000 steps.. an example of some of the atom's velocities in the 1st step is given at the end of this program). I will be highly obliged if any one can help me with this.I run this program on opensuse linux 11.3 version /32 bit/i586
error message:
Code: At line 124 of file v.autocorrelation.f (unit = 10, file = 'DFILE1') Fortran runtime error: End of file
Code: PROGRAM TCORR
COMMON / BLOCK1 / STORX, STORY, STORZ COMMON / BLOCK2 / VX, VY, VZ COMMON / BLOCK3 / VACF, ANORM C ******************************************************************* code....
