double gauss_value(double x, double mean, double sd, double down);
double like_gauss_by_line(double x, double mean, double sd, double down, 
		     double hist_height);
double like_gauss_by_box(double x, double mean, double sd, double down,
			 double hist_height);
double stock_like(double ratio, double x, double mean_neg, double sd_neg, 
	     double down_neg, double mean_pos, double sd_pos, double down_pos);
double ratio_PosToNeg_at_least_x(double x, double mean, double sd, double down,
	  double *area_pos_score_at_least_x, double *area_all_score_at_least_x,
	  double hist_height);
double fraction_of_positives_lower_than_x(double x, double mean, double sd,
	double down, double *area_to_x, double total_area, double hist_height);

double total_area_above_gauss(double min_x, double max_x, long *counts,
	  double mean, double sd, double down,long number_residues);
double total_area(double min_x, double max_x, long *counts, 
		  long number_residues);