0.1.0 / 2013-02-04

• Initial release:

** Delay line ** Biquad filters ** Envelope detector ** Conversion from dB-linear and linear-dB ** Linear interpolation ** Oscillator with selectable wave type (sine, square, triangle, sawtooth)

0.1.1 / 2013-02-04

Add EnvelopeDetector#attack_time= and EnvelopeDetector#release_time=

0.1.3 / 2013-02-18

• Added:

** A .cubic_hermite method to Interpolation class (implements cubic hermite polynomial interpolation) ** Window classes (Blackman, Hann, Hamming, etc.) ** DFT class, with .forward and .inverse methods. ** FFT class, with .forward and .inverse methods. ** Windowed sinc filter, a FIR filter for lowpass and highpass- ** Dual windowed sinc filter, a FIR filter for bandpass and bandstop. ** Discrete and Polynomial resampling classes, each with an .upsample method. ** Plotter class to make graphing with gnuplot easier. Has #plot_1d and #plot_2d methods. ** Signal class for testing convenience. Contains signal data and has convenience methods for plotting, correlation, energy, etc.

0.1.4 / 2013-02-19

Fixed gemspec to always depend on gnuplot (not just for development).

0.1.5 / 2013-02-19

Adjust project documentation.

0.1.6 / 2013-03-21

Update to be compatible with hashmake-0.1.6.

0.1.7 / 2013-04-18

Require all sample rate args to be Fixnum.

0.1.8 / 2013-05-03

Add Envelope and Extrema classes, for signal analysis.

0.1.9 / 2013-05-06

Add TukeyWindow. Add Signal#keep_frequences, Signal#remove_frequencies, and Plotter#plot_signals.

0.2.0 / 2013-05-21

Add instance methods to Signal class: #duration, #normalize, #derivative, #lowpass, #highpass, #bandpass, #bandstop, #plot_1d, and #plot_2d. Add Correlation class to find similarity between signals (used to find a feature in an image). Make envelopes smoother with polynomial upsampling. In Signal#envelope and Signal, always return a Signal object (so also remove make_signal flag).

0.2.1 / 2013-07-03

Update for compatibility with hashmake-0.2.0.