Approximatrix Forums — Error message: Segmentation fault

Re: Error message: Segmentation fault

null@example.com (jeff) — Thu, 25 Apr 2013 16:41:47 +0000

I just gave your code a try on my machine, and I'm not seeing any issue. Which version of Simply Fortran are you currently using? I just want to confirm you're on the latest version.

Doing the math manually, I can see that 64-bit wasn't actually necessary in your stripped-down example. Do you have debugging enabled already?

I've seen similar issues if the standard input and output unit numbers, 5 and 6, are used for file access via OPEN statements. Is anything of that nature currently occurring in your code?

Re: Error message: Segmentation fault

null@example.com (jin) — Thu, 25 Apr 2013 12:47:58 +0000

Yes, I am compiling in 64-bit mode with Windows7.
I did it as you recommended, but the same error message came out shortly after launching it.
You mentioned a few other things I can try. What are those?

I extracted some lines from my code following:

module globvar

!******* prohibit implicit variable declaration *******
implicit none

!******* meta parameter *******
real(8),parameter:: eps = 1.0d-10 !really small number
integer,parameter:: scr = 8 !screen output file number
integer,parameter:: out = 10 !output file number

!******* variables for approximation *******
integer,parameter:: ne=8 !number of earnings shocks
integer,parameter:: na = 800 !number of grid points

integer,parameter:: ni=ne*na

end module globvar

program main

use globvar
implicit none

real(8),dimension(1:ni,1:ni) :: matQ !matrix for modified policy rule

end program main

Re: Error message: Segmentation fault

null@example.com (jeff) — Wed, 24 Apr 2013 14:11:59 +0000

Are you compiling in 64-bit mode? That could be a simple fix.

If you already are in 64-bit mode, there might be a few other things you could try. For example, add the switch "-mcmodel=medium" to the Fortran compiler flags in the Project Options dialog. That allows more memory to be accessed by your program.

Error message: Segmentation fault

null@example.com (jin) — Wed, 24 Apr 2013 11:07:57 +0000

I compiled the code sucessfully, but I got the following error message shortly after I launched it.

---------------------------------------------------------------------------------------------------
Program received signal SIGSEGV: Segmentation fault - invalid memory reference.

Backtrace for this error:
#0 fffffffff
---------------------------------------------------------------------------------------------------

I think that this error message is related with the big matrix I defined as a real.
the size of the matrix is 6400*6400.
Before I introduced this big matrix, the code run well.
How can I solve the problem while using the big matrix?