derivative

#Derivative

##Description The Derivative class computes either the first or second order derivative of the input signal. The Derivative class is part of the Preprocessing Modules.

An example of computing the first and second derivative of a signal (sine wave) filtered using the Derivative class. The red signal is the original signal, the green signal is the first order derivative, and the blue signal is the second order derivative. Note that the three signals have been z-normalized for visualization purposes.

##Advantages The Derivative class is a good preprocessing module to use if you want a quick way of expressing the change in a signal.

##Disadvantages The derivative algorithm can be sensitive to noise in the original signal. It can therefore be useful to apply a small low pass filter to the signal before computing the derivative. The Derivative class can apply this low pass filter automatically, this can be enabled either via the classes constructor, or via the enableFiltering(bool) function.

##Example Derivative Example