CMake/Help/guide/tutorial/Step10/MathFunctions/mysqrt.cxx
Markus Ferrell 8ddf32196c Tutorial: Refactor MathFunctions code
Propagate the refactor in Step 10 MathFunctions through all of the
steps. Use MathFunctions/MathFunctions.cxx instead of Tutorial.cxx
to determine which sqrt library is called. Adds .h files which
correspond to their .cxx files by name.
2023-02-23 09:42:10 -05:00

38 lines
787 B
C++

#include <iostream>
#include "MathFunctions.h"
// include the generated table
#include "Table.h"
namespace mathfunctions {
namespace detail {
// a hack square root calculation using simple operations
double mysqrt(double x)
{
if (x <= 0) {
return 0;
}
// use the table to help find an initial value
double result = x;
if (x >= 1 && x < 10) {
std::cout << "Use the table to help find an initial value " << std::endl;
result = sqrtTable[static_cast<int>(x)];
}
// do ten iterations
for (int i = 0; i < 10; ++i) {
if (result <= 0) {
result = 0.1;
}
double delta = x - (result * result);
result = result + 0.5 * delta / result;
std::cout << "Computing sqrt of " << x << " to be " << result << std::endl;
}
return result;
}
}
}