t</h4>

<p>You can now construct a multivariate Gaussian p.d.f on the parameters of a model that
represents the result of a fit, from any <tt>RooFitResult</tt> object.
<pre>
   RooAbsPdf* paramPdf = fitresult->createHessePdf(RooArgSet(a,b)) ;
</pre>
<p>The returned object is an instance of the newly added class <tt>RooMultiVarGaussian</tt>, that can
model correlated Gaussian distributions in an arbitrary number of dimensions, given a
vector of mean values and a covariance matrix. Class <tt>RooMultivarGaussi