Go4Expert - Power Functions returning Zero

Hey all,

I think I must be brain damaged, because I am having the dumbest problem. I need a power function for a program, and every single one I use is returning zero at all times. I've tried the math.h pow() and two other functions, one recursive and one non-recursive.

The frustrating thing is that this is a tiny, trivial part of what I'm trying to do (find the root of a scalar equation with newton's method), and I can't even seem to get out of the gate.

I've tried compiling with g++ and gcc (need g++ for pow() of course), I've tried changing the value of j, swapping j and cx, changing the types of j and cx, and a whole bunch of other junk.

Any help would be greatly appreciated.

Here's the code, along with the debugging statements that prove to me that I'm getting the wrong answer.

-------------------------------------------

Code:

#include<math.h>



double calcPolyFunctionAtX(double cx);

double power(double px, int y);

double power2( double base, int exp );



/* ********************* */



/* Main */







int main()



{



double f;



/* unimportant stuff */



f = calcPolyFunctionAtX(x); 



/* unimportant stuff */

}





/* ********************* */

/* Function for calculating polynomial at x */



double calcPolyFunctionAtX(double cx){



int j;

double answer;

answer = 0;

double z;

z = 0;



        for(j=2; j<21; j++){



                z = pow(cx, j);



        printf("The value of cx is %d \n", cx); /* giving me correct values */

        printf("The value of j is %i \n\n", j); /* giving me correct values */



        /* all of these are giving me incorrect values */

        printf("The value of cx to the jth power by custom non-recursive power function is %d \n", power(cx, j) );

printf("The value of j to the cxth power by custom non-recursive power function is %d \n", power(j, cx) );



        printf("The value of cx to the jth power by built-in pow function is %d \n", pow(cx, j) );

printf("The value of j to the cxth power by built-in pow function is %d \n", pow(j, cx) ); 



        printf("The value of cx to the jth power by power2 recursive function is %d \n", power2(cx, j) );

printf("The value of j to the cxth power by power2 recursive function is %d \n", power2(j, cx) ); */







        }



/* other junk */



return answer;

}



double power(double px, int y){

double product = 1.0;

int g;



for(g=1; g<=y; g++) {

        product *= px;

        }



return product;



}



double power2( double base, int exp )

{



int i;

   if ( exp < 0 )

       return 1.0/power2(base, -exp);



  double product = 1.0;



  for ( i = 1 ; i <= exp ; i++ )

    product *= base;



  return product;

}