plectrum

commit 68b782deed8295eaed1ba3ef0365653fd8ad58ff
parent d0f249754303f8f025ca1cb0e5a9fc941bb5786c
Author: gstraube <gstraube@mailbox.org>
Date:   Sun, 23 Jul 2017 18:36:45 +0200

Create method for filtering samples by note

Diffstat:
M
app/src/main/java/com/github/cythara/Sampler.java
 | 
18
+++++++++++++++---
M
app/src/test/java/com/github/cythara/SamplerTest.java
 | 
18
++++++++++++++++++

2 files changed, 33 insertions(+), 3 deletions(-)
diff --git a/app/src/main/java/com/github/cythara/Sampler.java b/app/src/main/java/com/github/cythara/Sampler.java
@@ -2,6 +2,7 @@ package com.github.cythara;
 
 import android.support.annotation.Nullable;
 
+import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -10,14 +11,13 @@ class Sampler {
 
     static PitchDifference calculateAverageDifference(List<PitchDifference> samples) {
         Note mostFrequentNote = extractMostFrequentNote(samples);
+        List<PitchDifference> filteredSamples = filterByNote(samples, mostFrequentNote);
 
         double deviationSum = 0;
         int sameNoteCount = 0;
-        for (PitchDifference pitchDifference : samples) {
-            if (pitchDifference.closest == mostFrequentNote) {
+        for (PitchDifference pitchDifference : filteredSamples) {
                 deviationSum += pitchDifference.deviation;
                 sameNoteCount++;
-            }
         }
 
         if (sameNoteCount > 0) {
@@ -29,6 +29,18 @@ class Sampler {
         return null;
     }
 
+    static List<PitchDifference> filterByNote(List<PitchDifference> samples, Note note) {
+        List<PitchDifference> filteredSamples = new ArrayList<>();
+
+        for (PitchDifference sample : samples) {
+            if (sample.closest == note) {
+                filteredSamples.add(sample);
+            }
+        }
+
+        return filteredSamples;
+    }
+
     @Nullable
     static Note extractMostFrequentNote(List<PitchDifference> samples) {
         Map<Note, Integer> noteFrequencies = new HashMap<>();
diff --git a/app/src/test/java/com/github/cythara/SamplerTest.java b/app/src/test/java/com/github/cythara/SamplerTest.java
@@ -33,6 +33,24 @@ public class SamplerTest {
     }
 
     @Test
+    public void samples_are_filtered_correctly() {
+        List<PitchDifference> samples = new ArrayList<>();
+
+        samples.add(new PitchDifference(E2, 2D));
+        samples.add(new PitchDifference(E2, 2D));
+        samples.add(new PitchDifference(B3, 3D));
+        samples.add(new PitchDifference(E2, 2D));
+        samples.add(new PitchDifference(Note.G3, 4D));
+        samples.add(new PitchDifference(B3, 3D));
+
+        List<PitchDifference> filteredSamples = filterByNote(samples, B3);
+
+        for (PitchDifference sample : filteredSamples) {
+            assertThat(sample.closest, is(B3));
+        }
+    }
+
+    @Test
     public void the_most_frequent_note_is_extracted_correctly() throws Exception {
         List<PitchDifference> samples = new ArrayList<>();