edgefold.sci

来自「小波分解源代码」· SCI 代码 · 共 37 行

function extra = edgefold(which,xc,bp,bm)
// edgefold -- Perform folding projection with (+,-) polarity at EDGES
//  Usage
//    extra = edgefold(which,xc,bp,bm)
//  Inputs
//    which  string, 'left'/'right', indicating which edge we are at
//    xc     unfolded data, center window
//    bp     interior of window
//    bm     exterior of window
//  Outputs
//    extra  pseudo-left/right packet
//
//  Description
//    The result should be used as either left or right packet in
//    fold to ensure exact reconstruction at edges.
//
//  See Also
//    fold, unfold, CPSynthesis, CPImpulse
//
//  Copyright Aldo I Maalouf

	n = length2(xc);
	m = length2(bp);
	back  = n:-1:(n-m+1);
	front = 1:m;
	extra = xc.*0; 
	
	if string(which)=='left',
		extra(back) = xc(front) .* (1-bp)./bm;
	else
		extra(front) = -xc(back) .* (1-bp)./bm;
	end	

	endfunction