CMake/Tests/Tutorial/Step3/MathFunctions/mysqrt.cxx

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#include "MathFunctions.h"
#include <stdio.h>
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// a hack square root calculation using simple operations
double mysqrt(double x)
{
if (x <= 0) {
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return 0;
}
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double result;
double delta;
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result = x;
// do ten iterations
int i;
for (i = 0; i < 10; ++i) {
if (result <= 0) {
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result = 0.1;
}
delta = x - (result * result);
result = result + 0.5 * delta / result;
fprintf(stdout, "Computing sqrt of %g to be %g\n", x, result);
}
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return result;
}