Forward and Inverse Fast Wavelet Transforms Usage: output = wlet( signal, [output_type [, num_coeff [, direction]]]) Parameters: output_type is one of: 1 Output is one dimensional, and represents the raw result from the fast wavelet transform algorithm (wavelet coefficients). This is the default. 2 Output is two dimensional. This output format is convenient for displaying transformed data as a time-scale matrix (scalogram). num_coeff gives the number of filter coeffients used in approximating the wavelet. Possible values are 4, 12 or 20, and the default is 20. direction 1 Transform is forward, from time domain to time-scale domain. (default) -1 Transform is reverse, from time-scale domain to time domain. Two dimensional output can only be used with the forward transform, and the input to both forward and reverse transforms must be one-dimensional.