Home > NoiseTools > nt_bias_hi_amp.m

nt_bias_hi_amp

PURPOSE ^

[c0,c1]=bias_hi_amp(x,exponent) - covariance with and without hi-amp bias

SYNOPSIS ^

function [c0,c1,w]=bias_hi_amp(x,exponent)

DESCRIPTION ^

[c0,c1]=bias_hi_amp(x,exponent) - covariance with and without hi-amp bias

 y: high-amplitude component
 
 x: data set (2D or 3D)
 exponent: exponent to apply to squared difference (larger=peakier) [default: 0.5]

CROSS-REFERENCE INFORMATION ^

This function calls: This function is called by:

SOURCE CODE ^

0001 function [c0,c1,w]=bias_hi_amp(x,exponent)
0002 %[c0,c1]=bias_hi_amp(x,exponent) - covariance with and without hi-amp bias
0003 %
0004 % y: high-amplitude component
0005 %
0006 % x: data set (2D or 3D)
0007 % exponent: exponent to apply to squared difference (larger=peakier) [default: 0.5]
0008 
0009 if nargin<2; exponent=0.5; end
0010 
0011 % bias function emphasizes high-amplitude
0012 w=mean((x.^2).^exponent,2);
0013 ww=squeeze(min(w,[],1));
0014 w=nt_vecadd(squeeze(w),-ww');  % subtract minimum from each trial (sharpens the bias function)
0015 w=nt_fold(w(:),size(x,1));
0016 
0017 c0=nt_cov(x);
0018 % c1=tscov(vecmult(unfold(x),w));
0019 % save memory:
0020 c1=zeros(size(x,2));
0021 for k=1:size(x,3)
0022     c1=c1+nt_cov(nt_vecmult(x(:,:,k),w(:,:,k)));
0023 end

Generated on Mon 21-Oct-2013 11:27:02 by m2html © 2005