commit 298a83d3c0e79d621a81402dbccdaae0135e093a
parent 8e1bf4ccd7079e72c1a09ea4c00905d66aa45e37
Author: gstraube <gstraube@mailbox.org>
Date: Sat, 13 Jun 2020 11:49:14 +0200
Calculate note frequency (issue #30)
Diffstat:
3 files changed, 174 insertions(+), 0 deletions(-)
diff --git a/app/src/main/java/com/github/cythara/tuning/NoteFrequency.java b/app/src/main/java/com/github/cythara/tuning/NoteFrequency.java
@@ -0,0 +1,21 @@
+package com.github.cythara.tuning;
+
+import java.util.Arrays;
+import java.util.List;
+
+public class NoteFrequency {
+
+ private static List<String> notes =
+ Arrays.asList("C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B");
+
+ public static double getFrequency(String note, int octave) {
+ int semitonesPerOctave = 12;
+ int referenceOctave = 4;
+ double distance = semitonesPerOctave * (octave - referenceOctave);
+
+ distance += notes.indexOf(note) - notes.indexOf("A");
+
+ float referenceFrequency = 440;
+ return referenceFrequency * Math.pow(2, distance / 12);
+ }
+}
+\ No newline at end of file
diff --git a/app/src/test/java/com/github/cythara/tuning/NoteFrequencyTest.java b/app/src/test/java/com/github/cythara/tuning/NoteFrequencyTest.java
@@ -0,0 +1,43 @@
+package com.github.cythara.tuning;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+
+public class NoteFrequencyTest {
+
+ @Test
+ public void TestCalc() {
+
+ InputStream resourceAsStream = getClass().getResourceAsStream("note_frequencies.csv");
+ try (BufferedReader reader =
+ new BufferedReader(new InputStreamReader(resourceAsStream))) {
+ while (reader.ready()) {
+ String line = reader.readLine();
+ String[] components = line.split(",");
+ String noteWithOctave = components[0].split("/")[0];
+ String frequency = components[1];
+
+ String note = noteWithOctave.substring(0, 1);
+ String octave = noteWithOctave.substring(1);
+ if (noteWithOctave.contains("#")) {
+ note = noteWithOctave.substring(0, 2);
+ octave = noteWithOctave.substring(2);
+ }
+
+ double expectedFrequency = Double.parseDouble(frequency);
+ double actualFrequency = NoteFrequency.getFrequency(note, Integer.parseInt(octave));
+ Assert.assertEquals(expectedFrequency, actualFrequency, 0.01);
+
+ }
+ } catch (IOException e) {
+ Assert.fail(e.getMessage());
+ }
+
+ }
+
+}
+\ No newline at end of file
diff --git a/app/src/test/resources/com/github/cythara/tuning/note_frequencies.csv b/app/src/test/resources/com/github/cythara/tuning/note_frequencies.csv
@@ -0,0 +1,108 @@
+C0,16.35,2109.89
+C#0/Db0,17.32,1991.47
+D0,18.35,1879.69
+D#0/Eb0,19.45,1774.20
+E0,20.60,1674.62
+F0,21.83,1580.63
+F#0/Gb0,23.12,1491.91
+G0,24.50,1408.18
+G#0/Ab0,25.96,1329.14
+A0,27.50,1254.55
+A#0/Bb0,29.14,1184.13
+B0,30.87,1117.67
+C1,32.70,1054.94
+C#1/Db1,34.65,995.73
+D1,36.71,939.85
+D#1/Eb1,38.89,887.10
+E1,41.20,837.31
+F1,43.65,790.31
+F#1/Gb1,46.25,745.96
+G1,49.00,704.09
+G#1/Ab1,51.91,664.57
+A1,55.00,627.27
+A#1/Bb1,58.27,592.07
+B1,61.74,558.84
+C2,65.41,527.47
+C#2/Db2,69.30,497.87
+D2,73.42,469.92
+D#2/Eb2,77.78,443.55
+E2,82.41,418.65
+F2,87.31,395.16
+F#2/Gb2,92.50,372.98
+G2,98.00,352.04
+G#2/Ab2,103.83,332.29
+A2,110.00,313.64
+A#2/Bb2,116.54,296.03
+B2,123.47,279.42
+C3,130.81,263.74
+C#3/Db3,138.59,248.93
+D3,146.83,234.96
+D#3/Eb3,155.56,221.77
+E3,164.81,209.33
+F3,174.61,197.58
+F#3/Gb3,185.00,186.49
+G3,196.00,176.02
+G#3/Ab3,207.65,166.14
+A3,220.00,156.82
+A#3/Bb3,233.08,148.02
+B3,246.94,139.71
+C4,261.63,131.87
+C#4/Db4,277.18,124.47
+D4,293.66,117.48
+D#4/Eb4,311.13,110.89
+E4,329.63,104.66
+F4,349.23,98.79
+F#4/Gb4,369.99,93.24
+G4,392.00,88.01
+G#4/Ab4,415.30,83.07
+A4,440.00,78.41
+A#4/Bb4,466.16,74.01
+B4,493.88,69.85
+C5,523.25,65.93
+C#5/Db5,554.37,62.23
+D5,587.33,58.74
+D#5/Eb5,622.25,55.44
+E5,659.25,52.33
+F5,698.46,49.39
+F#5/Gb5,739.99,46.62
+G5,783.99,44.01
+G#5/Ab5,830.61,41.54
+A5,880.00,39.20
+A#5/Bb5,932.33,37.00
+B5,987.77,34.93
+C6,1046.50,32.97
+C#6/Db6,1108.73,31.12
+D6,1174.66,29.37
+D#6/Eb6,1244.51,27.72
+E6,1318.51,26.17
+F6,1396.91,24.70
+F#6/Gb6,1479.98,23.31
+G6,1567.98,22.00
+G#6/Ab6,1661.22,20.77
+A6,1760.00,19.60
+A#6/Bb6,1864.66,18.50
+B6,1975.53,17.46
+C7,2093.00,16.48
+C#7/Db7,2217.46,15.56
+D7,2349.32,14.69
+D#7/Eb7,2489.02,13.86
+E7,2637.02,13.08
+F7,2793.83,12.35
+F#7/Gb7,2959.96,11.66
+G7,3135.96,11.00
+G#7/Ab7,3322.44,10.38
+A7,3520.00,9.80
+A#7/Bb7,3729.31,9.25
+B7,3951.07,8.73
+C8,4186.01,8.24
+C#8/Db8,4434.92,7.78
+D8,4698.63,7.34
+D#8/Eb8,4978.03,6.93
+E8,5274.04,6.54
+F8,5587.65,6.17
+F#8/Gb8,5919.91,5.83
+G8,6271.93,5.50
+G#8/Ab8,6644.88,5.19
+A8,7040.00,4.90
+A#8/Bb8,7458.62,4.63
+B8,7902.13,4.37
