On Wed, 02 Feb 2000, Rohit Sharma wrote:
>Hey gang ,
>
> I have a c program to calculate sin of a no using exp series (DSP
>assigmment :)).It compile properly and then dumps core. When I use gdb to
>analyse the core Gdb dumps core!!!.
On my system, it didn't dump core, ran well, but generated wrong output. (sin pi/2 =
a very large
number > 10^6). Heres a corrected version with more terms in the series.
-----cut here-----
/* Working code */
#include <stdio.h>
void main (void)
{
float mysin(float x);
float no,finalval;
printf("Enter no\n");
scanf("%f",&no);
/* Small degree to rad convertor */
no = no*3.14159/180; /* Because I hate entering rad values :)*/
finalval=mysin(no);
printf("answer is %f\n\n",finalval);
}
float mysin(float x)
{
float term,value;
int i, sign_int;
term = x;
i = 1;
value = term; /* Set equal to first term of sine series */
/* Originalcode */
/* while (i<=10)
{
value=((-1)*term*x*x)/((i+1)*(i+2));
sum=sum+value;
i=i+2;
term=value;
}*/
/* x-x^3/3!+x^5/5!...*/
sign_int = -1; /* Can be eliminated, but KISS , -1 because we have already considered
first term*/
for(i=1;i<21;i+=2)
{
term = term*x*x/((i+1)*(i+2)); /* Get next element of series */
value += sign_int*term; /* Add to the value of sine */
sign_int = -1*sign_int; /* Switch sign */
}
return(value);
}
-----cut here-----
/* Comment your programs */
Devdas Bhagat
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