Module utils

Compute the modulation of a parameter centered. Extremums are set to zero.

Args :

• serie : list or numpy array containing the serie.
• wLen : Length of the analyzis window in samples.
• withLog : Whether compute the var() or log(var()) .

Returns :

• modul : Modulation of the serie.

Grenerate a Mel Filter-Bank

Args :

• nbFilters : Number of filters.
• fftLen : Length of the frequency range.
• sr : Sampling rate of the signal to filter.

Returns :

• filterbank : fftLen x nbFilters matrix containing one filter by column. The filter bank can be applied by matrix multiplication (Use numpy *dot* function).

Generate a triangle filter.

Args :

• length : length of the filter.

returns :

• triangle : triangle filter.

Compute entropy of a serie using the histogram method.

Args :
    - serie     : Serie on witch compute the entropy
    - nbins     : Number of bins of the histogram
    - base      : Base used for normalisation
    - approach  : String in the following set : {unbiased,mmse}
                  for un-biasing value.

Returns :
    - estimate  : Entropy value
    - nbias     : N-bias of the estimate
    - sigma     : Estimated standard error

Raises :
    A warning in case of unknown 'approach' value.
    No un-biasing is then performed