function p=leq(x,t,Pref)% LEQ  Computes the sequence of short-time RMS powers (Leq) of a signal. %     P = LEQ(X,T) is a length LENGTH(X)/T column vector whose %     elements are the RMS powers (Leq's) of length T frames of X. %     The powers are expressed in dB with 1 as reference level. %     LEQ(X,T,REF) uses REF as the reference level for the dB %     scale. If a RMS power is equal to zero, a NaN is returned %     for its dB value. %% Author: Christophe Couvreur, Faculte Polytechnique de Mons (Belgium)%         couvreur@thor.fpms.ac.be% Last modification: Aug. 24, 1997, 4:00pm.m = floor(length(x)/t);p = zeros(m,1);for i = 1:m  p(i) = sum(x((i-1)*t+1:i*t).^2)/t; endidx = (p>0);if (nargin < 3)  Pref = 1; endif ~isempty(idx)   p(idx) = 10*log10(p(idx)/Pref);  p(~idx) = NaN*ones(sum(~idx),1);else  p = NaN*ones(m,1);end