signal extraction
Y=wkeep(x,[L],[type]) Y=wkeep(x,[L],[FIRST]) Y=wkeep(M,[S],[indexVector])
double vector
double matrix
length integer
extraction manner, 'l' for left, 'r' for right, and 'c' for center
index integer from which extraction starts.
size integer vector containing row size and column size wanted
row and column index integer vector from which extraction starts.
extraction result
wkeep is an utility function for both vector and matrix extraction. For vector extraction, extractions will be aligned to the right, left or center based on optional argument type. So does matrix extraction.