chore: move benchpress to @angular/benchpress

modules/@angular/benchpress/src/statistic.ts

@@ -0,0 +1,43 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import {Math} from '@angular/facade/src/math';
+
+export class Statistic {
+  static calculateCoefficientOfVariation(sample, mean) {
+    return Statistic.calculateStandardDeviation(sample, mean) / mean * 100;
+  }
+
+  static calculateMean(samples: number[]) {
+    var total = 0;
+    // TODO: use reduce
+    samples.forEach(x => total += x);
+    return total / samples.length;
+  }
+
+  static calculateStandardDeviation(samples: number[], mean) {
+    var deviation = 0;
+    // TODO: use reduce
+    samples.forEach(x => deviation += Math.pow(x - mean, 2));
+    deviation = deviation / (samples.length);
+    deviation = Math.sqrt(deviation);
+    return deviation;
+  }
+
+  static calculateRegressionSlope(
+      xValues: number[], xMean: number, yValues: number[], yMean: number) {
+    // See http://en.wikipedia.org/wiki/Simple_linear_regression
+    var dividendSum = 0;
+    var divisorSum = 0;
+    for (var i = 0; i < xValues.length; i++) {
+      dividendSum += (xValues[i] - xMean) * (yValues[i] - yMean);
+      divisorSum += Math.pow(xValues[i] - xMean, 2);
+    }
+    return dividendSum / divisorSum;
+  }
+}