covf = gpcovarf(net, x1, x2)
covf = gpcovarf(net, x1, x2) takes
a Gaussian Process data structure net together with
two matrices x1 and x2 of input vectors,
and computes the matrix of the covariance function values
covf.
gp, gpcovar, gpcovarp, gperr, gpgradCopyright (c) Ian T Nabney (1996-9)