Include note name in frequency axis trackers

This applies to the FFT Spectrum, 2D Spectrogram, and Octave Spectrogram.

friture/histplot.py

@@ -54,7 +54,7 @@ def __init__(self, parent, engine):
         self._histplot_data.vertical_axis.name = "PSD (dB A)"
         self._histplot_data.vertical_axis.setTrackerFormatter(lambda x: "%.1f dB" % (x))
         self._histplot_data.horizontal_axis.name = "Frequency (Hz)"
-        self._histplot_data.horizontal_axis.setTrackerFormatter(lambda x: "%.0f Hz" % (x))
+        self._histplot_data.horizontal_axis.setTrackerFormatter(self.format_frequency)
 
         self._histplot_data.vertical_axis.setRange(0, 1)
         self._histplot_data.horizontal_axis.setRange(44, 22000)
@@ -89,6 +89,9 @@ def __init__(self, parent, engine):
 
         self.setLayout(plotLayout)
 
+    def format_frequency(self, freq: float) -> str:
+        return f'{freq:.0f} Hz ({fscales.freq_to_note(freq)})'
+
     def on_status_changed(self, status):
         if status == QQuickWidget.Error:
             for error in self.quickWidget.errors():

friture/imageplot.py

@@ -196,7 +196,7 @@ def __init__(self, parent):
         self.colorScale.setTitle("PSD (dB A)")
 
         self.canvasWidget = CanvasWidget(self, self.verticalScaleTransform, self.horizontalScaleTransform)
-        self.canvasWidget.setTrackerFormatter(lambda x, y: "%.2f s, %d Hz" % (x, y))
+        self.canvasWidget.setTrackerFormatter(self.trackerFormatter)
 
         plotLayout = QtWidgets.QGridLayout()
         plotLayout.setSpacing(0)
@@ -221,6 +221,9 @@ def __init__(self, parent):
         # need to replot here for the size Hints to be computed correctly (depending on axis scales...)
         self.update()
 
+    def trackerFormatter(self, x: float, y: float) -> str:
+        return f'{x:.2f} s, {y:.0f} Hz ({fscales.freq_to_note(y)})'
+
     def addData(self, freq, xyzs, last_data_time):
         self.plotImage.addData(freq, xyzs, self.freqscale, last_data_time)
 

friture/plotting/frequency_scales.py

@@ -137,6 +137,15 @@ def _minorTicks(trueMin, trueMax, firstMajorTick, majorTickInterval) -> list[flo
 
         return ticks
 
+def freq_to_note(freq: float) -> str:
+    if np.isnan(freq) or freq <= 0:
+        return ""
+    # number of semitones from C4
+    # A4 = 440Hz and is 9 semitones above C4
+    semitone = round(np.log2(freq/440) * 12) + 9
+    octave = int(np.floor(semitone / 12)) + 4
+    notes = ["C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B"]
+    return f'{notes[semitone % 12]}{octave}'
 
 class Logarithmic(object):
     NAME = 'Logarithmic'

friture/spectrumPlotWidget.py

@@ -12,6 +12,7 @@
 
 from friture.audiobackend import SAMPLING_RATE
 from friture.plotting.coordinateTransform import CoordinateTransform
+from friture.plotting.frequency_scales import freq_to_note
 from friture.spectrum_data import Spectrum_Data
 from friture.filled_curve import CurveType, FilledCurve
 from friture.store import GetStore
@@ -49,9 +50,7 @@ def __init__(self, parent, engine):
         self._spectrum_data.vertical_axis.name = "PSD (dB)"
         self._spectrum_data.vertical_axis.setTrackerFormatter(lambda x: "%.1f dB" % (x))
         self._spectrum_data.horizontal_axis.name = "Frequency (Hz)"
-        self._spectrum_data.horizontal_axis.setTrackerFormatter(
-            self.trackerFormatterPitch
-        )
+        self._spectrum_data.horizontal_axis.setTrackerFormatter(self.format_frequency)
 
         self._spectrum_data.vertical_axis.setRange(0, 1)
         self._spectrum_data.horizontal_axis.setRange(0, 22000)
@@ -143,25 +142,8 @@ def set_baseline_displayUnits(self, baseline):
     def set_baseline_dataUnits(self, baseline):
         self._baseline = Baseline.DATA_ZERO
 
-    def freq_to_note(self, freq: float) -> str:
-        if freq == 0:
-            return ""
-        # number of semitones from C4
-        # A4 = 440Hz and is 9 semitones above C4
-        semitone = round(np.log2(freq / 440) * 12) + 9
-        octave = int(np.floor(semitone / 12)) + 4
-        notes = ["C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B"]
-        return f"{notes[semitone % 12]}{octave}"
-
-    def trackerFormatterPitch(self, x):
-        try:
-            note = self.freq_to_note(x)
-        except ValueError:
-            return ""
-        if x < 1000:
-            return "%d Hz (%s)" % (int(x), note)
-        else:
-            return "%.1f kHz (%s)" % (x / 1000, note)
+    def format_frequency(self, freq: float) -> str:
+        return f'{freq:.0f} Hz ({freq_to_note(freq)})'
 
     def setdata(self, x, y, fmax, fpitch):
         if not self.paused:
@@ -173,7 +155,7 @@ def setdata(self, x, y, fmax, fpitch):
                 text, self.normHorizontalScaleTransform.toScreen(fmax)
             )
             self._spectrum_data.setFpitch(
-                f"{int(fpitch)} Hz ({self.freq_to_note(fpitch)})",
+                self.format_frequency(fpitch),
                 self.normHorizontalScaleTransform.toScreen(fpitch),
             )