Cochran (#7)

* feat: add cochran outline function

* feat: find squareDeviations

* feat: calculating c value

* feat: n & p value added

* feat: cochran algorithm finished ✅

* test: cochran test added ✅

* fix: some style change, refactor code

* feat: cochranCriticalValue 1/2 created

* feat: cochran critival value finish 1/1 ✅

* fix: cochran algorithm update by new criticalValues

* test: cochran test add & finish ✅

* set generatedCode to es5

* refactor cochran method

* move cochran test to separate file

* rename nonoutlier to correct

Co-authored-by: Ahmet Özışık <ozisikahmet@gmail.com>

Author: burakodabas

rollup.config.js

@@ -17,6 +17,7 @@ export default [
         file: `${name}.js`,
         format: 'cjs',
         sourcemap: true,
+        generatedCode: 'es5',
       },
     ],
   }),

src/algorithms/cochran.ts

@@ -0,0 +1,53 @@
+import { get } from 'lodash';
+import { CochranResult } from '../types';
+import { standardDeviation } from 'simple-statistics';
+import cochranCriticalValues from './cochranCriticalValues';
+
+export function Cochran(values: Array<number[]>): CochranResult | null {
+  /* p -> numune sayısı  */
+  const pValue = values.length;
+
+  /* n -> yapılan tekrar,test sayısı */
+  const nValue = values[0].length;
+
+  const onePercentCriticalValue = get(
+    cochranCriticalValues,
+    `${nValue}.1%.${pValue}`
+  );
+
+  const fivePercentCriticalValue = get(
+    cochranCriticalValues,
+    `${nValue}.5%.${pValue}`
+  );
+
+  if (!onePercentCriticalValue || !fivePercentCriticalValue) {
+    return null;
+  }
+
+  const squareDeviations = values
+    .map((value) => {
+      return standardDeviation(value);
+    })
+    .map((value) => {
+      return value * value;
+    });
+
+  const maxDeviation = Math.max.apply(null, squareDeviations);
+  const sumOfSquareDeviations = squareDeviations.reduce((a, b) => a + b, 0);
+
+  const cValue = maxDeviation / sumOfSquareDeviations;
+
+  if (cValue < fivePercentCriticalValue) {
+    return CochranResult.Correct;
+  }
+
+  if (cValue < onePercentCriticalValue && cValue > fivePercentCriticalValue) {
+    return CochranResult.Straggler;
+  }
+
+  if (cValue > onePercentCriticalValue) {
+    return CochranResult.Outlier;
+  }
+
+  return null;
+}