Discussion Forum

Hi,

I had been using printf() in an external material code for debugging purposes to output data to the screen. This worked but slowed down the whole thing. This was done in MS Visual C. I didn't try fprintf().

Cheers Edgar

Hi, Thanks! But how do I link MS visual C with COMSOL to output data to a screen?

The printf() statement is part of the source code for the dll you generate with Visual C. No link of MS Visual C and Comsol needed. Comsol simply calls the dll and executes it.

Here is a code example, adapt it to your needs. Remove the outer commenting: /* */. It ran under Windows 7. Don't close the console manually. This will crash Comsol. It closes when Comsol closes.

/*

//START Debugging Console Window output

//The following code opens a console window for debugging purposes; mainly to check for

//correct reception of submitted fields and parameters

//Handle this with care - it can crash your machine - backup often!

static int counter = 1;

if (counter == 1)

{

AllocConsole();

freopen("CONOUT$", "w", stdout);

printf("COMSOL Multiphysics at work \r\n");

printf("Opened Console after first call to external material routine \r\n\n");

}

if(counter % 10000 == 0)

printf("Call Nr.: %7d Br = %-+5.3f Bphi = %-+5.3f Bz = %-+5.3f\r", counter, B[0], B[1], B[2]);

counter = counter + 1;

//END Debugging Console Window output

*/

Just saw that the forum software messes up the format, so added some linefeeds.

I should add, that you can use any C development system that can generate a dll, it doesn't need to be MS Visual C.

Hi Edgar,

That worked for me! Thanks a lot.

Good to hear. Good luck!