/**
* Given a bg frequency matrix and a phospho count matrix, we will convert the bg
* freq matrix into a binomial matrix. No reason to keep a bg freq matrix, so we will recycle.
*/
void convert_bg_freqs_to_binomial(MATRIX_T* phospho_count, MATRIX_T* bg_freqs, int num_phospho_seqs) {
int i;
int j;
for (i = 0; i < get_num_rows(bg_freqs); ++i) {
for (j = 0; j < get_num_cols(bg_freqs); ++j) {
double p = get_matrix_cell_defcheck(i, j, bg_freqs);
double cxj = get_matrix_cell_defcheck(i, j, phospho_count);
int n = num_phospho_seqs;
double log_value = log_betai(cxj, n-cxj+1, p);
set_matrix_cell_defcheck(i, j, log_value, bg_freqs);
}
}
}
/*************************************************************************
* Compute the enrichment of a central window
*************************************************************************/
static double window_enrichment(int window,
double window_sites, long total_sites,
int bins, int max_bins) {
// p-value vars
double log_p_value;
// calculate the log p-value
if (window_sites == 0 || bins == max_bins) {
log_p_value = 0; // pvalue of 1
} else {
double n_trials, n_successes, p_success;
n_trials = (double)total_sites;
n_successes = window_sites;
p_success = (double)bins / (double)max_bins;
log_p_value = log_betai(n_successes, n_trials - n_successes + 1.0, p_success);
DEBUG_FMT(DUMP_VERBOSE, "window: %4d p_success: %20.15e "
"successes: %10.4f trials: %5.0f = log_p-value: %10.5e\n", window,
p_success, n_successes, n_trials, log_p_value);
}
return log_p_value;
}
