lotwin

 lotwin.m

 Window function for the lapped orthgonal transform

0001 % lotwin.m
0002 %
0003 % Window function for the lapped orthgonal transform
0004 %
0005 
0006 function g0 = lotwin(t, eta, varargin)
0007 
0008 if nargin > 1
0009     eta = varargin{1};
0010 else
0011     eta = 0.25;
0012 end
0013 eta1 = eta; 
0014 if nargin > 2
0015     eta1 = varargin{1};
0016 end
0017 
0018 % length
0019 %L = 1;
0020 
0021 % We should eventually generalize to this parameterization
0022 % edgewidth
0023 %eta = 1/4;
0024 % g0 = zeros(size(t));
0025 % ti = find((t>=-1/4)&(t<=1/4));
0026 % g0(ti) = betaedge(2*t(ti) + 1/2);
0027 % ti = find((t>1/4)&(t<=3/4));
0028 % g0(ti) = 1;
0029 % ti = find((t>3/4)&(t<=5/4));
0030 % g0(ti) = betaedge(5/2-2*t(ti));
0031 
0032 
0033 % General value of eta
0034 g0 = zeros(size(t));
0035 tl = find((t>=-eta)&(t<=eta));
0036 g0(tl) = betaedge((t(tl)+eta)/(2*eta));
0037 tc = find((t>=eta)&(t<=1-eta1));
0038 g0(tc) = 1;
0039 tr = find((t>=1-eta1)&(t<=1+eta1));
0040 g0(tr) = betaedge((-t(tr)+1+eta1)/(2*eta1));
0041 
0042 % verify
0043 % figure; plot([g0(tl) g0(tr) g0(tl).^2+g0(tr).^2])