Kahan summation: Difference between revisions

=={{header|Java}}==

{{trans|Kotlin}}

As is noted in the Kotlin implementation, the JVM does not provide the desired decimal type, so the alternate implementation is provided instead.

<lang Java>public class KahanSummation {

private static float kahanSum(float... fa) {

float sum = 0.0f;

float c = 0.0f;

for (float f : fa) {

float y = f - c;

float t = sum + y;

c = (t - sum) - y;

sum = t;

}

return sum;

}

private static float epsilon() {

float eps = 1.0f;

while (1.0f + eps != 1.0f) eps /= 2.0f;

return eps;

}

public static void main(String[] args) {

float a = 1.0f;

float b = epsilon();

float c = -b;

System.out.println("Epsilon = " + b);

System.out.println("(a + b) + c = " + ((a + b) + c));

System.out.println("Kahan sum = " + kahanSum(a, b, c));

}

}</lang>

{{out}}

<pre>Epsilon = 5.9604645E-8

(a + b) + c = 0.99999994

Kahan sum = 1.0</pre>