Question

Hello i have code for parameter estimation in C language. The problem is that the code is developed for floating point numbers and i want it for integer values The code is

#include "stdio.h"
#include "conio.h"
#include "math.h"
#define N 30
double g(double b, double s[], double sn, double sk);
double gdash(double b, double s[], double sn);
main()
{
int i;
double sk=0;
double s_avg,g1,g2,a;
double

s[N]={30.02,31.46,53.93,55.29,58.72,71.92,77.07,80.9,101.9,114.87,115.34,
121.57,124.96,134.07,136.25,151.78,177.5,180.29,182.21,186.34,256.81,
273.88,277.87,453.93,535.0,537.27,552.9,673.68,704.49,738.68};
double b[N];
clrscr();
sk=0, s_avg=0.0;
printf("\n Input observations :\n");
for(i=0;i<N;i++)
sk=sk+s[i];
s_avg=sk/N;
b[0]=log(4)/s_avg;
printf("\nb=%f\n",b[0]);
i=-1;
do
{
i=i+1;
g1=g(b[i],s,s[N-1],sk);
g2=gdash(b[i],s,s[N-1]);
b[i+1]=b[i]-(g1/g2);
printf("\nb[%d]= %lf b[%d]= %lf",i,b[i],i+1,b[i+1]);
printf("\n\t\t\t|b[%d]-b[%d]| = %lf",i+1,i,fabs(b[i+1]-b[i]));
}while((fabs(b[i+1]-b[i])>=0.0001));
a=((N)/(1-exp(-b[i+1]*(s[N-1]))));
printf("\n\nb[%d] = %lf is the M.L.E of b = %lf a=%lf",i+1,b[i+1],b[i+1],a);
getch();
}
double g(double b, double s[N], double sn, double sk)
{
int k;
double v3=0.0,c3,c4,g_val;
for(k=0;k<N-1;k++)
v3=v3+(s[k]);
c3=(N*sn*(exp(-b*sn)))/(1-exp(-b*sn));

g_val=v3-(N/b)+c3;
return g_val;
}
double gdash(double b,double s[N], double sn)
{
double gdash_val,c3;
c3=(N*sn*sn)*((1/(1-exp(-b*sn)))+(exp(-b*sn))/
(1-exp(-b*sn))*(1-exp(-b*sn)))*exp(-b*sn);
gdash_val=(N/(b*b))+c3;
return gdash_val;
}
In this code the double array has declared for double

s[N]={30.02,31.46,53.93,55.29,58.72,71.92,77.07,80.9,101.9,114.87,115.34,
121.57,124.96,134.07,136.25,151.78,177.5,180.29,182.21,186.34,256.81,
273.88,277.87,453.93,535.0,537.27,552.9,673.68,704.49,738.68};
where as i want values to be entered in
s[n] are {1,3,8,9,11,16,19,25,27,29,32,32,26,38,39,39,41,42,42}

Answer 1

// I HAVE ONLY COMMENTED THE CHANGES I HAVE DONE IN THE CODE

#include "stdio.h"

#include "conio.h"

#include "math.h"

#define N 30

//here we have changed the signature of function from

//(double b, double s[], double sn, double sk) to (double b, int s[], int sn, double sk)

//in order to accept integer values of s[n].

double g(double b, int s[], int sn, double sk);

//here we have changed the signature of function from

//(double b, double s[], double sn) to (double b, int s[], int sn)

//in order to accept integer values of s[n].

double gdash(double b, int s[], int sn);

//I have changed main() to int main due to compiler issues

int main()
{

int i;

double sk,s_avg,g1,g2,a;

//This is the int s[n] input as required by you

int s[N]={30,31,53,55,58,71,77,80,101,114,115,121,124,134,136,151,177,180,182,186,256,273,277,453,535,537,552,673,704,738};

//Your unchanged code starts here.

double b[N];

sk=0, s_avg=0.0;

printf("\n Input observations :\n");

for(i=0;i<N;i++) sk=sk+(s[i]*1.0); //I have multiplied s[i] to 1.0 to explicitly type cast s[i] as a double.

s_avg=sk/N;

b[0]=log(4)/s_avg;

printf("\nb=%f\n",b[0]);

i=-1;

do

{

i=i+1;

g1=g(b[i],s,s[N-1],sk);

g2=gdash(b[i],s,s[N-1]);

b[i+1]=b[i]-(g1/g2);

printf("\nb[%d]= %lf b[%d]= %lf",i,b[i],i+1,b[i+1]);

printf("\n\t\t\t|b[%d]-b[%d]| = %lf",i+1,i,fabs(b[i+1]-b[i]));

}while((fabs(b[i+1]-b[i])>=0.0001));

a=((N)/(1-exp(-b[i+1]*(s[N-1]))));

printf("\n\nb[%d] = %lf is the M.L.E of b = %lf a=%lf",i+1,b[i+1],b[i+1],a);

return 0;

//Your unchanged code ends here

}

double g(double b, int s[N], int sn, double sk)

{

int k;

double v3=0.0,c3,c4,g_val;

for(k=0;k<N-1;k++) v3=v3+(s[k]*1.0); //I have multiplied s[k] to 1.0 to explicitly type cast s[k] as a double.

double x=sn*1.0; //I have multiplied sn to 1.0 to explicitly type cast sn as a double.

c3=(N*x*(exp(-b*x)))/(1-exp(-b*x));

g_val=v3-(N/b)+c3;

return g_val;

}

double gdash(double b,int s[N], int sn)

{

double gdash_val,c3;

double x=sn*1.0; //I have multiplied sn to 1.0 to explicitly type cast sn as a double.

c3=(N*x*x)*((1/(1-exp(-b*x)))+(exp(-b*x))/(1-exp(-b*x))*(1-exp(-b*x)))*exp(-b*x);

gdash_val=(N/(b*b))+c3;

return gdash_val;

}