ref: 504e4423e780b4a3e7904e406c43612b96a15702
dir: /FIR-POLY/timeline.m/
function [t, mt, w] = timeline (len, stretch)
if (stretch < 0 || stretch > 1)
error ("stretch out of range [0, 1].\n");
endif
# Mofified time
x_w = 0.2 ;
x = [-0.5 -0.2 0.2 0.5];
y = [-0.5 -0.4 -0.1 0.5];
p = polyfit (x, y, 4);
t = linspace (-0.5, 0.5, 100);
y = polyval (p,t);
plot (t, y)
return
mt = ((1 - stretch) * t + stretch * t.^2) - 0.5 ;
# Basically a Nuttall window
ak = [0.42323 0.49755 0.07922] ;
w = zeros (1, len) ;
k = 0 ;
for a = ak,
w = w + a * cos (2 * pi * k * mt) ;
k += 1 ;
endfor
w = fliplr (w / len) ;
# Linear t
t = linspace (-(len-2)/2, (len-2)/2, len) / len ;
end
# Do not edit or modify anything in this comment block.
# The following line is a file identity tag for the GNU Arch
# revision control system.
#
# arch-tag: 830f701e-5e9c-478a-a929-609513d4b1a6