Mega Code Archive
Compare double base on precision
<![CDATA[
#include <iostream>
#include <cmath>
using namespace std;
bool doubleEquals(double left, double right, double epsilon) {
return (fabs(left - right) < epsilon);
}
bool doubleLess(double left, double right, double epsilon, bool orequal = false) {
if (fabs(left - right) < epsilon) {
return (orequal);
}
return (left < right);
}
bool doubleGreater(double left, double right, double epsilon, bool orequal = false) {
if (fabs(left - right) < epsilon) {
return (orequal);
}
return (left > right);
}
int main( ) {
double first = 0.33333333;
double second = 1.0 / 3.0;
cout << first << endl;
cout << second << endl;
cout << boolalpha << (first == second) << endl;
cout << doubleEquals(first, second, .0001) << endl;
cout << doubleLess(first, second, .0001) << endl;
cout << doubleGreater(first, second, .0001) << endl;
cout << doubleLess(first, second, .0001, true) << endl;
cout << doubleGreater(first, second, .0001, true) << endl;
}
0.333333
0.333333
false
true
false
true
]]>