dyadic downsampling
Y=dyaddown(x,[EVEN_ODD]) Y=dyaddown(M,[EVEN_ODD],[type]) Y=dyaddown(M,[type],[EVEN_ODD])
dyaddown is an utility function for dyadic downsampling. if EVEN_ODD is even, even index entries of input will be kept. Otherwise, odd index entries will be kept. Default is even. Optional argumet type is especially for matrix input downsampling.
Roger Liu and Isaac Zhi