boinc/samples/wrappture/fermi.cpp

40 lines
910 B
C++

// fermi.cpp -- core calculation of Rappture example app-fermi
#include <stdlib.h>
#include <stdio.h>
#include <cmath>
#include <unistd.h>
int main(int argc, char * argv[]) {
double T, Ef, E, dE, kT, Emin, Emax, f;
FILE *fo = fopen("fermi_out.dat", "w");
if (!fo) {
fprintf(stderr, "Failed to open output file\n");
exit(-1);
}
// Check args
if (3 != argc) {
fprintf(stderr, "Usage: %s T Ef\n", argv[0]);
exit(-1);
}
T = atof(argv[1]); // in K
Ef = atof(argv[2]); // in eV
kT = 8.61734e-5 * T;
Emin = Ef - 10.0*kT;
Emax = Ef + 10.0*kT;
E = Emin;
dE = 0.005*(Emax-Emin);
while (E < Emax) {
f = 1.0/(1.0 + exp((E - Ef)/kT));
fprintf(fo, "%f %f\n",f, E);
fprintf(stdout, "=RAPPTURE-PROGRESS=>%d\n", (int)((E-Emin)/(Emax-Emin)*100));
E = E + dE;
}
fclose(fo);
return 0;
}