ata.

model.N = length(data.ydata);  % total number of observations
model.S20 = model.sigma2;      % prior mean for sigma2
model.N0  = 4;                 % prior accuracy for sigma2

%%
% The |options| structure has settings for the MCMC run. We need at
% least the number of simulations in |nsimu|. Here we also set the
% option |updatesigma| to allow automatic sampling and estimation of the
% error variance. The option |qcov| sets the initial covariance for
% the Gaussian proposal density of the MCMC sample