Merge pull request #60 from sintel-dev/frequency_primitive

Frequency primitive

sigpro/basic_primitives.py

@@ -29,6 +29,13 @@ def __init__(self):
  super().__init__("sigpro.transformations.frequency.fft.fft")
 
 
+class FFTFreq(primitive.FrequencyTransformation):
+ """FFT Freq primitive class."""
+
+ def __init__(self):
+ super().__init__("sigpro.transformations.frequency.fftfreq.fft_freq")
+
+
 class FFTReal(primitive.FrequencyTransformation):
  """FFTReal primitive class."""
 

sigpro/primitives/sigpro/transformations/frequency/fftfreq/fft_freq.json

@@ -0,0 +1,30 @@
+{
+ "name": "sigpro.transformations.frequency.fftfreq.fft_freq",
+ "primitive": "sigpro.transformations.frequency.fftfreq.fft_freq",
+ "classifiers": {
+ "type": "transformation",
+ "subtype": "frequency"
+ },
+ "produce": {
+ "args": [
+ {
+ "name": "amplitude_values",
+ "type": "numpy.ndarray"
+ },
+ {
+ "name": "sampling_frequency",
+ "type": "float"
+ }
+ ],
+ "output": [
+ {
+ "name": "amplitude_values",
+ "type": "numpy.ndarray"
+ },
+ {
+ "name": "frequency_values",
+ "type": "numpy.ndarray"
+ }
+ ]
+ }
+}

sigpro/transformations/frequency/fftfreq.py

@@ -0,0 +1,21 @@
+"""SigPro Transformations Frequency module."""
+
+import numpy as np
+
+
+def fft_freq(amplitude_values, sampling_frequency):
+ """Compute the Frequency having FFT values.
+
+ Args:
+ amplitude_values (np.ndarray):
+ A numpy array with the fft values.
+ sampling_frequency (int or float):
+ Sampling frequency value passed in Hz.
+ Returns:
+ tuple:
+ * `amplitude_values (numpy.ndarray)`
+ * `frequency_values (numpy.ndarray)`
+ """
+ frequency_values = np.fft.fftfreq(len(amplitude_values), 1 / sampling_frequency)
+
+ return np.array(amplitude_values), np.array(frequency_values)

tests/unit/transformations/frequency_time/test_stft.py

@@ -19,7 +19,7 @@ def test_stft():
  expected_time_values_len = 3
  value = amplitude_values[0][0]
 
- assert type(value) == np.complex128
+ assert isinstance(value, np.complex128)
  assert len(amplitude_values) == expected_amplitude_values_len
  assert len(frequency_values) == expected_frequency_values_len
  assert len(time_values) == expected_time_values_len
@@ -39,7 +39,7 @@ def test_stft_real():
  expected_time_values_len = 3
  value = amplitude_values[0][0]
 
- assert type(value) == np.float64
+ assert isinstance(value, np.float64)
  assert len(amplitude_values) == expected_amplitude_values_len
  assert len(frequency_values) == expected_frequency_values_len
  assert len(time_values) == expected_time_values_len