Hi:
Could you please paste the equation and show us the parameters you want fit? Since we can calculate the landau density value but I don't know which parameter you want to know.
As for landau distribution, you can call a NAG function in Origin C, g01mtc, to get the density function value. Here is an Origin C example:
#include <Origin.h>
#include <OC_nag8.h>
void test_landau_density(double x)
{
double d = g01mtc(x);
printf("y on %f = %f\n", x, d);
}
For more info about this NAG function, please search g01mtc in Origin Programming help to download the PDF document.
As for defining an Origin C fitting function, please read this tutorial.
For more info about Origin C, please read our Programming Guide.
Hope this helps.
Thanks
Larry
OriginLab