Diversity prediction theorem: Difference between revisions
→{{header|JavaScript}}
Line 363:
Diversity : 10.500
</pre>
=={{header|Java}}==
{{trans|Kotlin}}
<lang java>import java.util.Arrays;
public class DiversityPredictionTheorem {
private static double square(double d) {
return d * d;
}
private static double averageSquareDiff(double d, double[] predictions) {
return Arrays.stream(predictions)
.map(it -> square(it - d))
.average()
.orElseThrow();
}
private static String diversityTheorem(double truth, double[] predictions) {
double average = Arrays.stream(predictions)
.average()
.orElseThrow();
return String.format("average-error : %6.3f%n", averageSquareDiff(truth, predictions))
+ String.format("crowd-error : %6.3f%n", square(truth - average))
+ String.format("diversity : %6.3f%n", averageSquareDiff(average, predictions));
}
public static void main(String[] args) {
System.out.println(diversityTheorem(49.0, new double[]{48.0, 47.0, 51.0}));
System.out.println(diversityTheorem(49.0, new double[]{48.0, 47.0, 51.0, 42.0}));
}
}</lang>
{{out}}
<pre>average-error : 3.000
crowd-error : 0.111
diversity : 2.889
average-error : 14.500
crowd-error : 4.000
diversity : 10.500</pre>
=={{header|JavaScript}}==
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