def train_interval_mel_features(interval_dict,pattern = '{:s}',nr_fft = 100,
len_fft = 1024, nr_mel_bins = 100, min_freq_wanted = 200, max_freq_wanted = 8000,
is_return_fit = False):
"""
Calculate the mel spectrogram features for each interval in the interval_dict and return a feature matrix X
of ndim = [nr_intervals,nr_features]
Parameters:
-----------
interval_dict : dict
Dictionary which keys point to a file_path via pattern and which values are list of lists of [start_time,end_time]
for trinaing intervals
pattern : string
A formatting string to map from the interval_dict keys to file_paths
nr_fft : int
The number of ffts in each stft calculation
len_fft : int
The length of each of the nr_fft fourier transforms for each stft
nr_mel_bins : int
The number of bins in which the mel spectrum is to be divided in
min_freq_wanted, max_freq_wanted : float
The lowest/highest frequency in the returned mel spectrum
Returns:
--------
X : ndarray
Array containing the flattened stft in mel spectrum for each interval in interval_dict.
Each row corresponds to one interval and each colum to one feature of the flattened mel spectrum
"""
# -- The total number of intervals in the dictionary
nr_intervals = np.array([len(interval_dict[file_key]) for file_key in interval_dict]).sum()
X = np.zeros((nr_intervals,nr_mel_bins*nr_fft))
t = np.zeros((nr_intervals,2))
i=0
file_interval_tuple = ()
for file_key in interval_dict:
file_name = pattern.format(file_key)
print file_name
fs,data = spwav.read(file_name)
data=data-np.mean(data)
for time_interval in interval_dict[file_key]:
file_interval_tuple = file_interval_tuple+((file_key,time_interval),)
sf = int(time_interval[0]*fs)
ef = int(time_interval[1]*fs)
spectrum = stft.calc_stft(data[sf:ef],fs = fs, nr_fft = nr_fft, len_fft = len_fft)[0]
X[i,:] = mel.stft_to_mel_freq(spectrum,fs=fs,len_fft=len_fft,nr_mel_bins = nr_mel_bins,
min_freq_wanted = min_freq_wanted , max_freq_wanted= max_freq_wanted)[0].flatten()
t[i] = time_interval
i+=1
if is_return_fit:
return X,file_interval_tuple
return X
def calc_pattern_correlation_chunked(data,pattern,fs,freq_fft_bins ,chunk_len_s = 45,
len_fft = 1024, nr_ffts_per_s = 100, pattern_len_s = 2):
"""
Calculate the average correlation between the stft of a timeseries and a pattern over a certain
frequency range. Used for data generation for machine learning as input for peak finding algorithms.
Parameters
----------
data : 1D ndarray
Timeseries
pattern : ndarray
The timeseries pattern which is used to calculate the correlation with data
fs : float
The sample frequency (frames per second) of the data
freq_fft_bins : list
The frequency bins used for the correlation between pattern and the stft of the data
chunk_len_s : int
The length in seconds for each chunked stft.
len_fft : int
The length of each fft calculation.
nr_ffts_per_s : int
Number of ffts per second in the stft.
pattern_len_s : int
Length of the pattern in seconds
Returns
-------
peaks : 1D ndarray
The concatenated array of the correlation between data and pattern
"""
n_frames_chunk,_,_,sec_per_sample,overlap = stft.calc_nr_frames(chunk_len_s,fs,len_fft,chunk_len_s*nr_ffts_per_s)
# -- By giving the overlap, the length of the pattern is not necessarily pattern_len_s*nr_ffts_per_s anymore
pattern = stft.calc_stft(pattern,0,pattern.shape[0], fs, pattern_len_s*nr_ffts_per_s,overlap=overlap)[0]
# -- z-score the pattern
pattern = (pattern-np.mean(pattern)) / np.std(pattern)
#q75, q50, q25 = np.percentile(pattern, [75 ,50, 25])
#iqr = q75 - q25
#pattern = 1/(1+np.exp(-(pattern -q50)/(iqr/1.35)))
# plt.matshow(pattern, origin='lower')
# exit()
end_frame = 0
start_frame = 0
while end_frame < data.shape[0] - n_frames_chunk:
start_frame = end_frame
end_frame = end_frame+n_frames_chunk
spectrum = stft.calc_stft(data,start_frame,end_frame, fs,chunk_len_s*nr_ffts_per_s)[0]
#spectrum = (spectrum - np.mean(spectrum))/np.std(spectrum)
print 'spectrum.shape: ',spectrum.shape
for i in freq_fft_bins:
if i == freq_fft_bins[0]:
tmp = np.correlate(spectrum[i,:], pattern[i,:], mode='same', old_behavior=False)
print 'tmp.shape: ',tmp.shape
print 'spectrum[i,:].shape:' ,spectrum[i,:].shape
else :
tmp += np.correlate(spectrum[i,:], pattern[i,:], mode='same', old_behavior=False)
print 'tmp.shape: ',tmp.shape
print 'spectrum[i,:].shape:' ,spectrum[i,:].shape
if start_frame == 0:
peaks = tmp
else:
peaks = np.hstack((peaks,tmp))
return peaks
def calc_pattern_correlation_chunked(data,
pattern,
fs,
freq_fft_bins,
chunk_len_s=45,
len_fft=1024,
nr_ffts_per_s=100,
pattern_len_s=2):
"""
Calculate the average correlation between the stft of a timeseries and a pattern over a certain
frequency range. Used for data generation for machine learning as input for peak finding algorithms.
Parameters
----------
data : 1D ndarray
Timeseries
pattern : ndarray
The timeseries pattern which is used to calculate the correlation with data
fs : float
The sample frequency (frames per second) of the data
freq_fft_bins : list
The frequency bins used for the correlation between pattern and the stft of the data
chunk_len_s : int
The length in seconds for each chunked stft.
len_fft : int
The length of each fft calculation.
nr_ffts_per_s : int
Number of ffts per second in the stft.
pattern_len_s : int
Length of the pattern in seconds
Returns
-------
peaks : 1D ndarray
The concatenated array of the correlation between data and pattern
"""
n_frames_chunk, _, _, sec_per_sample, overlap = stft.calc_nr_frames(
chunk_len_s, fs, len_fft, chunk_len_s * nr_ffts_per_s)
# -- By giving the overlap, the length of the pattern is not necessarily pattern_len_s*nr_ffts_per_s anymore
pattern = stft.calc_stft(pattern,
0,
pattern.shape[0],
fs,
pattern_len_s * nr_ffts_per_s,
overlap=overlap)[0]
# -- z-score the pattern
pattern = (pattern - np.mean(pattern)) / np.std(pattern)
#q75, q50, q25 = np.percentile(pattern, [75 ,50, 25])
#iqr = q75 - q25
#pattern = 1/(1+np.exp(-(pattern -q50)/(iqr/1.35)))
# plt.matshow(pattern, origin='lower')
# exit()
end_frame = 0
start_frame = 0
while end_frame < data.shape[0] - n_frames_chunk:
start_frame = end_frame
end_frame = end_frame + n_frames_chunk
spectrum = stft.calc_stft(data, start_frame, end_frame, fs,
chunk_len_s * nr_ffts_per_s)[0]
#spectrum = (spectrum - np.mean(spectrum))/np.std(spectrum)
print 'spectrum.shape: ', spectrum.shape
for i in freq_fft_bins:
if i == freq_fft_bins[0]:
tmp = np.correlate(spectrum[i, :],
pattern[i, :],
mode='same',
old_behavior=False)
print 'tmp.shape: ', tmp.shape
print 'spectrum[i,:].shape:', spectrum[i, :].shape
else:
tmp += np.correlate(spectrum[i, :],
pattern[i, :],
mode='same',
old_behavior=False)
print 'tmp.shape: ', tmp.shape
print 'spectrum[i,:].shape:', spectrum[i, :].shape
if start_frame == 0:
peaks = tmp
else:
peaks = np.hstack((peaks, tmp))
return peaks
def train_interval_mel_features(interval_dict,
pattern='{:s}',
nr_fft=100,
len_fft=1024,
nr_mel_bins=100,
min_freq_wanted=200,
max_freq_wanted=8000,
is_return_fit=False):
"""
Calculate the mel spectrogram features for each interval in the interval_dict and return a feature matrix X
of ndim = [nr_intervals,nr_features]
Parameters:
-----------
interval_dict : dict
Dictionary which keys point to a file_path via pattern and which values are list of lists of [start_time,end_time]
for trinaing intervals
pattern : string
A formatting string to map from the interval_dict keys to file_paths
nr_fft : int
The number of ffts in each stft calculation
len_fft : int
The length of each of the nr_fft fourier transforms for each stft
nr_mel_bins : int
The number of bins in which the mel spectrum is to be divided in
min_freq_wanted, max_freq_wanted : float
The lowest/highest frequency in the returned mel spectrum
Returns:
--------
X : ndarray
Array containing the flattened stft in mel spectrum for each interval in interval_dict.
Each row corresponds to one interval and each colum to one feature of the flattened mel spectrum
"""
# -- The total number of intervals in the dictionary
nr_intervals = np.array(
[len(interval_dict[file_key]) for file_key in interval_dict]).sum()
X = np.zeros((nr_intervals, nr_mel_bins * nr_fft))
t = np.zeros((nr_intervals, 2))
i = 0
file_interval_tuple = ()
for file_key in interval_dict:
file_name = pattern.format(file_key)
print file_name
fs, data = spwav.read(file_name)
data = data - np.mean(data)
for time_interval in interval_dict[file_key]:
file_interval_tuple = file_interval_tuple + (
(file_key, time_interval), )
sf = int(time_interval[0] * fs)
ef = int(time_interval[1] * fs)
spectrum = stft.calc_stft(data[sf:ef],
fs=fs,
nr_fft=nr_fft,
len_fft=len_fft)[0]
X[i, :] = mel.stft_to_mel_freq(
spectrum,
fs=fs,
len_fft=len_fft,
nr_mel_bins=nr_mel_bins,
min_freq_wanted=min_freq_wanted,
max_freq_wanted=max_freq_wanted)[0].flatten()
t[i] = time_interval
i += 1
if is_return_fit:
return X, file_interval_tuple
return X