betaedge

PURPOSE

betaedge.m

SYNOPSIS

function b = betaedge(t)

DESCRIPTION

 betaedge.m

 Transition function for a lapped orthogonal transform.

 beta(t) = 0   t < 0
         = sqrt(35t^4-84t^5+70t^6-20t^7)   0<t<1
         = 1   t > 1

 (if -1<t<1, then beta(t) needs to be shifted by 1 and scaled by 1/2, i.e, t --> (t+1)/2)

CROSS-REFERENCE INFORMATION

This function calls:

This function is called by:

lotwin lotwin.m

SOURCE CODE

0001 % betaedge.m
0002 %
0003 % Transition function for a lapped orthogonal transform.
0004 %
0005 % beta(t) = 0   t < 0
0006 %         = sqrt(35t^4-84t^5+70t^6-20t^7)   0<t<1
0007 %         = 1   t > 1
0008 %
0009 % (if -1<t<1, then beta(t) needs to be shifted by 1 and scaled by 1/2, i.e, t --> (t+1)/2)
0010 
0011 function b = betaedge(t)
0012 
0013 b = zeros(length(t),1);
0014 ti = find((t>=0)&(t<=1));
0015 b(ti) = sqrt(35*t(ti).^4 - 84*t(ti).^5 + 70*t(ti).^6 - 20*t(ti).^7);
0016 b(t>1) = 1;
0017