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a36731c634
* Print message when using the table * Remove duplicated comment * Remove HAVE_LOG and HAVE_EXP checks, use generated table instead
37 lines
786 B
C++
37 lines
786 B
C++
#include "MathFunctions.h"
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#include <iostream>
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// include the generated table
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#include "Table.h"
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namespace mathfunctions {
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namespace detail {
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// a hack square root calculation using simple operations
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double mysqrt(double x)
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{
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if (x <= 0) {
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return 0;
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}
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// use the table to help find an initial value
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double result = x;
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if (x >= 1 && x < 10) {
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std::cout << "Use the table to help find an initial value " << std::endl;
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result = sqrtTable[static_cast<int>(x)];
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}
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// do ten iterations
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for (int i = 0; i < 10; ++i) {
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if (result <= 0) {
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result = 0.1;
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}
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double delta = x - (result * result);
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result = result + 0.5 * delta / result;
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std::cout << "Computing sqrt of " << x << " to be " << result << std::endl;
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}
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return result;
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}
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}
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}
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