// Calculate P-value based on Fisher's exact test.
double fpval(double nm, double nn, double bm, double bn)
{
double contingency_table[4] = {nm, nn, bm, bn};
// stuff for Fisher's test.
int nrow = 2;
int *nrowp = &nrow;
int ncol = 2;
int *ncolp = &ncol;
double expected = -1.0;
double percnt = 100.0;
double emin = 0.0;
double prt = 0.0;
double *expectedp = &expected;
double *percntp = %
double *eminp = &emin;
double *prtp = &prt;
double pvalue = 0.0;
double *pvaluep = &pvalue;
int workspace = 300000;
int *workspacep = &workspace;
fexact(nrowp, ncolp, contingency_table, nrowp, expectedp, percntp, eminp, prtp, pvaluep, workspacep);
return pvalue;
}
double fexact_two_sided_pvalue(const std::vector<int> &twotwoTable)
{
// This is specific for 2x2 tables. contingency_table = matrix(twotwoTable, 2, 2, byrow = T)
double contingency_table[4] = {0, 0, 0, 0};
for (int i = 0; i != 4; ++i) contingency_table[i] = twotwoTable[i];
//stuff for Fisher's test
int nrow = 2;
int ncol = 2;
double expected = -1.0;
double percnt = 100.0;
double emin = 0.0;
double prt = 0.0;
double pvalue = 0.0;
int workspace = 300000;
fexact(&nrow, &ncol, contingency_table, &nrow, &expected, &percnt, &emin, &prt, &pvalue, &workspace);
return pvalue;
}