function powerarr (s, binsize, colour)
if nargin == 1
binsize = 5.0; colour = 'b';
elseif nargin == 2
colour = 'b';
end
if binsize < 0
fprintf ('Invalid bin size');
end
[f pow] = dave_bin_FFT(s(:,1), s(:,2), binsize); % Taken from Steinmitz/Koch
pow = abs(pow).^2;
len = round(length(f));
loglog (f(1:len), pow(1:len), colour)
end