ISRIDGEPOINT Finds wavelet ridge points using one of several criterion. ISRIDGEPOINT is a low-level function called by RIDGEWALK. BOOL=ISRIDGEPOINT(W,FS,CHI,STR) where W is a wavelet transform matrix at *radian* frequecies FS, finds all ridge points of W with amplitudes |W| exceeding the amplitude cutoff A. Several different different ridge defintions may be used and are specified by STR. BOOL is a matrix of the same size as W, which is equal to one for those elements of W which are ridge points, and zero otherwise. STR may be either of the following: 'phase' Rate of transform change of phase definition 'amplitude' Maxima of transfom amplitude definition For all definitions, ISRIDGEPOINT rejects spurious ridge points. These tend to occur on the flanks of interesting signals, and reflect the wavelet structure rather than the signal structure. A ridge point is considered spurious if either it is located at an amplitude minima, or if the frequency anomaly (transform frequency minus scale frequency) is a maximum. See also RIDGEQUANTITY, RIDGEWALK. __________________________________________________________________ This is part of JLAB --- type 'help jlab' for more information (C) 2006--2015 J.M. Lilly --- type 'help jlab_license' for details