Add note2root() and note2octave()

src/essentia/essentiamath.h

@@ -762,6 +762,15 @@ inline std::string midi2note(int midiNoteNumber) {
   return closest_note;
 }
 
+inline std::string note2root(std::string note) {
+    return note.substr(0, note.size()-1);
+}
+
+inline int note2octave(std::string note) {
+    char octaveChar = note.back();
+    return octaveChar - '0';
+}
+
 inline Real midi2hz(int midiNoteNumber, Real tuningFrequency) {
   return tuningFrequency * powf(2, (midiNoteNumber - 69) / 12.0);
 }

src/python/essentia/utils.py

@@ -82,6 +82,12 @@ def hz2cents(arg1, arg2):
 def midi2note(arg):
     return _essentia.midi2note( _c.convertData(arg, _c.Edt.INTEGER) )
 
+def note2root(arg):
+    return _essentia.note2root( _c.convertData(arg, _c.Edt.STRING) )
+
+def note2octave(arg):
+    return _essentia.note2octave( _c.convertData(arg, _c.Edt.STRING) )
+
 def equivalentKey(arg):
     return _essentia.equivalentKey( _c.convertData(arg, _c.Edt.STRING) )
 
@@ -107,6 +113,7 @@ def derivative(array):
             'mel2hz', 'hz2mel',
             'midi2hz', 'hz2midi',
 	    'cents2hz', 'hz2cents',
+	    'note2root', 'note2octave',
             'midi2note',
             'postProcessTicks',
             'normalize', 'derivative',

src/python/globalfuncs.cpp

@@ -457,6 +457,31 @@ midiToNote(PyObject* notUsed, PyObject* arg) {
   return PyString_FromString( c_note );
 }
 
+static PyObject*
+noteToRoot(PyObject* notUsed, PyObject* arg) {
+
+  if (!PyString_Check(arg)) {
+    PyErr_SetString(PyExc_TypeError, (char*)"expecting arguments (string note)");
+    return NULL;
+  }
+
+  std::string root = note2root( PyString_AS_STRING(arg) );
+  const char *c_root = root.c_str();
+  return PyString_FromString( c_root );
+}
+
+static PyObject*
+noteToOctave(PyObject* notUsed, PyObject* arg) {
+
+  if (!PyString_Check(arg)) {
+    PyErr_SetString(PyExc_TypeError, (char*)"expecting arguments (string note)");
+    return NULL;
+  }
+
+  int octave = note2octave( PyString_AS_STRING(arg) );
+  return PyLong_FromLong( int(octave) );
+}
+
 static PyObject*
 getEquivalentKey(PyObject* notUsed, PyObject* arg) {
   if (!PyString_Check(arg)) {
@@ -1073,6 +1098,8 @@ static PyMethodDef Essentia__Methods[] = {
   { "hz2cents",      hzToCents,        METH_VARARGS, "Returns the cents distance between two frequencies in Hz" },
   { "cents2hz",      centsToHz,        METH_VARARGS, "Returns the frequency from a frequency in Hz and cents distance" },
   { "midi2note",     midiToNote,       METH_O, "Converts a midi note number to note applying the international pitch standard (A4=440Hz)" },
+  { "note2root",     noteToRoot,       METH_O, "Returns the root of a note" },
+  { "note2octave",   noteToOctave,     METH_O, "Returns the octave of a note" },
   { "lin2db",        linToDb,          METH_O, "Converts a linear measure of power to a measure in dB" },
   { "db2lin",        dbToLin,          METH_O, "Converts a dB measure of power to a linear measure" },
   { "db2pow",        dbToPow,          METH_O, "Converts a dB measure of power to a linear measure" },

test/src/unittests/base/test_utils.py

@@ -139,6 +139,16 @@ def testMidiToNote(self):
         expected_note = "A4"
         self.assertEqual(expected_note, midi2note(midi))
 
+    def testNoteToRoot(self):
+        note = "A4"
+        expected_root = note[0]
+        self.assertEqual(expected_root, note2root(note))
+
+    def testNoteToOctave(self):
+        note = "A4"
+        expected_octave = int(note[1])
+        self.assertEqual(expected_octave, note2octave(note))
+
 
 suite = allTests(TestUtils)