C/Data Type/Array Double

Summing 100 data values

<source lang="cpp">

1. include <stdio.h>

int main() {

 double data[100];
 double sum = 0.0;
 int i = 0;
 double sign = 1.0;
 printf("\nYou entered the values:\n");
 for(i = 1 ; i<=100 ; i++){
   data[i-1] = 1.0/(2*i*(2*i+1)*(2*i+2));
 }
 for(i = 0 ; i<100 ; i++)
 {
   sum += sign*data[i];
   sign = -sign;
 }
 printf("\nResult is %.4lf\n", 4.0*sum+3);

}

      </source>

Summing reciprocals of five values

<source lang="cpp">

1. include <stdio.h>

void main() {

 double data[5];
 double sum = 0.0;
 int i = 0;
 printf("Enter five values separated by spaces:\n");
 for(i = 0 ; i<5 ; i++)
   scanf("%lf", &data[i]);
 printf("\nYou entered the values:\n");
 for(i = 0 ; i<5 ; i++)
   printf("%10.2lf", data[i]);
 printf("\n");
 for(i = 0 ; i<5 ; i++)
 {
   sum += 1.0/data[i];
   if(i>0)
     printf(" + ");
   printf("1/%.2lf", data[i]);
 }
 printf(" = %lf\n", sum);

}

      </source>

using a 2-dimensional array of doubles

<source lang="cpp">

1. include <stdio.h>
2. include <math.h>
3. define iBASES 6
4. define iEXPONENTS 3
5. define iBASE 0
6. define iRAISED_TO 1
7. define iRESULT 2

int main( ) {

double dpowers[iBASES][iEXPONENTS]={
  1.1, 1, 0,
  2.2, 2, 0,
  3.3, 3, 0,
  4.4, 4, 0,
  5.5, 5, 0,
  6.6, 6, 0
};
int irow_index;
for(irow_index=0; irow_index < iBASES; irow_index++)
  dpowers[irow_index][iRESULT] =
    pow(dpowers[irow_index][iBASE],
    dpowers[irow_index][iRAISED_TO]);
for(irow_index=0; irow_index < iBASES; irow_index++) {
  printf("    %d\n",(int)dpowers[irow_index][iRAISED_TO]);
  printf(" %2.1f = %.2f\n\n",dpowers[irow_index][iBASE],
                             dpowers[irow_index][iRESULT]);
}
return(0);

}

 </source>