#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#include <stdio.h>
#include <math.h>
#include <string.h>
#include <errno.h>
#include "yagi.h"

/* The function performance gives a performance rating for the antenna
between 0 and 1, for use in a genetic algorithm to get performance. All
parameters are roughly linear */ 

extern int errno;
extern double Zo;

double performance(struct flags flag, struct performance_data data, struct performance_data max, struct performance_data weight, struct performance_data start)
{
	double a, x_err, fb,swr,product_of_weights;
	struct performance_data perform;
	double max_fb;
	int items=0;
	memset((char*) &perform,1,sizeof(perform));
	/* perform.gain=1.0; perform.fb=1.0; perform.swr=1.0;
	perform.fb=1.0; perform.r=1.0; perform.x=1.0;
	perform.sidelobe=1.0; */
	product_of_weights=1.0;
	weight.sidelobe/=100.0;
	/* To normalise the fitness, we must divide by the products of the
	weights, so this must be found. */
	if(weight.gain!=0.0)
		product_of_weights=weight.gain;
	if(weight.fb!=0.0)
		product_of_weights*=weight.fb;
	if(weight.r!=0.0)
		product_of_weights*=weight.r;
	if(weight.x!=0.0)
		product_of_weights*=weight.x;
	if(weight.swr!=0.0)
		product_of_weights*=weight.swr;
	if(weight.sidelobe!=0.0)
		product_of_weights*=weight.sidelobe;
	if(  ((flag.Wflg&GAIN)==GAIN) ||  ((flag.gflg&GAIN)==GAIN) )
	{
		/* gain=pow(10.0,data.gain/10.0);       
		start_gain=pow(10.0,(start.gain-1.0)/10.0);       
		max_gain=pow(10.0,max.gain/10.0);
		if(gain>1.2*max_gain)
			gain=max_gain;
		perform.gain=weight.gain*(gain-start_gain)/(max_gain-start_gain); */
		perform.gain=weight.gain*(data.gain-5)/(max.gain-5);
		/* printf("perform.g= %f g=%f\n", perform.gain, data.gain);  */
		if(perform.gain < 0)
			perform.gain=0.0;
		items++;
	}
	if(  ((flag.Wflg&FB)==FB) ||  ((flag.gflg&FB)==FB) )
	{
		fb=pow(10.0,data.fb/10.0);       
		max_fb=pow(10.0,max.fb/10.0);
		if((fb>max_fb) &(!flag.Oflg))
			fb=max_fb; 
		perform.fb=weight.fb*fb/max_fb; 
		items++;
	}
	if(  ((flag.Wflg&RESISTANCE)==RESISTANCE) || ((flag.gflg&RESISTANCE)==RESISTANCE))
	{
		perform.r=(1-pow(fabs(Zo-data.r)/Zo,0.25));  
		if(data.r<0.7*Zo || data.r > 1.4*Zo)
			perform.r/=10.0;
		items++;
	}
	if(  ((flag.Wflg&REACTANCE)==REACTANCE) || ((flag.gflg&REACTANCE)==REACTANCE))
	{
		x_err=fabs(data.x)/Zo;  
		if(x_err > 1.0)
			x_err=1.0;
		perform.x=1-pow(x_err,0.28);
		items++;
	}
	if(  ((flag.Wflg&VSWR)==VSWR) ||  ((flag.gflg&VSWR)==VSWR) )
	{
		swr=data.swr;
		/* The follwing, fitness=(1-((swr-1)/(swr+1))^2), gives a fitness
		proportional to the fraction of power radiated, assuming all 
		reflected power is absorbed. Unfortunately, it gives too high a#
		fitness to a poor VSWR, so was abandoned */
		/* perform.swr=weight.swr*(1-pow((swr-1.0)/(swr+1.0),2.0) ) ;    */


		/* The folloing is an imperical relationship developed by me, by writing
		a number of VSWR's down (1.0, 1.1, 1.5, 2.0, 3.0 and infinity and 
		writing down what I donsidered their fitness (1.0, 0.9, 0.8, 0.5 and 0.1)
		then fitting a polynomial thru em. The fitness dont work out exactly
		as above, but they seem reasonable. This has a maximum value of 
		0.98220 at VSWR=1.0, but I wont bother addeding the scale factor
		1/.98220 = 1.0181, since this will not improve things - only slow the 
		program a bit! */
		/* perform.swr=2.86298/(swr*swr) - 1.88078/(swr*swr*swr); */
		/* Another imperical one */
		/* if(swr > 7.2925)
			perform.swr=1.0/(swr);
		else */
			perform.swr=1.0-log10(swr); 
		/* if(swr>7.76124)
			perform.swr=1.0/(swr*swr);
		else
			perform.swr=1.0-log10(swr); */
			
		/* printf("swr=%f fit = %f\n", swr, perform.swr);  */
		items++;
	}
	if(  ((flag.Wflg&SIDE_LOBE_LEVEL)==SIDE_LOBE_LEVEL) ||  ((flag.gflg&SIDE_LOBE_LEVEL)==SIDE_LOBE_LEVEL) )
	{
		/* sidelobe_level=pow(10.0,data.sidelobe/10.0);       
		max_sidelobe=pow(10.0,max.sidelobe/10.0);
		if((sidelobe_level>max_sidelobe) & !flag.Oflg)
			sidelobe_level=max_sidelobe;  
		perform.sidelobe=weight.sidelobe*sidelobe_level/max_sidelobe; */
		perform.sidelobe=weight.sidelobe*data.sidelobe/max.sidelobe; 
		items++;
	}
	/* a=(perform.gain*perform.fb*perform.r*perform.x*perform.swr*perform.sidelobe)/product_of_weights; */
	a=(perform.gain+perform.fb+perform.r+perform.x+perform.swr+perform.sidelobe)/(double) items;
#ifdef DEBUG
	if(errno)
	{
		fprintf(stderr,"Errno =%d in perform.c\n", errno);
		exit(1);
	}
#endif
	return(a);
}