It is wanted of me to implement the following function:
void calc ( double* a, double* b, int r, int c, double (*f) (double) )
Parameters a, r, c and f are input and b is output. “a” and “b” are two-dimensional matrices with “r” rows and “c” columns. “f” is a function pointer which can point to any function of the following type:
double function‐name ( double x ) {
…
}
Function calc converts every element in matrix a, i.e., aij, to bij=f(aij) in matrix b.
I implement the calc function as follows, and put it in a program to test it:
#include <stdlib.h>
#include <iostream>
using namespace std;
double f1(double x){
return x * 1.7;
}
void calc (double* a, double* b, int r, int c, double (*f) (double))
{
double input;
double output;
for(int i=0; i<r*c; i++)
{
input = a[i];
output = (*f)(input);
b[i] = output;
}
}
int main()
{
// Input array:
int r=3;
int c=4;
double* a = new double[r*c];
double* b = new double[r*c];
// Fill "a" with test data
//...
for (int i=0; i<r*c; i++)
{
a[i] = i;
}
// Transform a to b
calc(a, b, r, c, f1);
// Print to test if the results are OK
//...
for (int i=0; i<r*c; i++)
{
b[i] = i;
}
return 0;
}
The problem is, I can't compile it. This is the output of DevC++ when I click on Compile and Execute button:
What's wrong?
I appreciate any comment to make the implementation more efficient.
