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#include "MathFunctions.h"
#include <iostream>
// include the generated table
#include "Table.h"
#include <cmath>
namespace mathfunctions {
namespace detail {
// a hack square root calculation using simple operations
double mysqrt(double x)
{
if (x <= 0) {
return 0;
}
// if we have both log and exp then use them
#if defined(HAVE_LOG) && defined(HAVE_EXP)
double result = exp(log(x) * 0.5);
std::cout << "Computing sqrt of " << x << " to be " << result << " using log"
<< std::endl;
#else
// use the table to help find an initial value
double result = x;
if (x >= 1 && x < 10) {
result = sqrtTable[static_cast<int>(x)];
}
// if we have both log and exp then use them
// 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;
}
#endif
return result;
}
}
}
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