function y = interpolate(x,t)% INTERPOLATE Return the linearily interpolated element value% corresponding to a time value.%% Y = INTERPOLATE(X,T)  Return element value Y at time location T in signal% object X.% $Id: interpolate.m 63 2005-01-10 14:20:08Z mairas $I = ceil((t-x.time.begin)*x.time.fs+1);y=zeros(1,length(I));for i=1:length(I)  imin=I(i)-1;  imax=I(i);  if imin<1    imin=1;    imax=2;  end  ts=x.time.t(imin:imax);  ys=x.s(imin:imax);  tinv=[-1 1;1 0];  p=ys*tinv;  y(i)=polyval(p,x.time.fs*(t(i)-ts(1)));end