net = glmtrain(net, options, x, t)
uses
the iterative reweighted least squares (IRLS)
algorithm to set the weights in the generalized linear model structure
net
. This is a more efficient alternative to using glmerr
and glmgrad
and a non-linear optimisation routine through
netopt
.
Note that for linear outputs, a single pass through the
algorithm is all that is required, since the error function is quadratic in
the weights. The error function value at the final set of weights is returned
in options(8)
.
Each row of x
corresponds to one
input vector and each row of t
corresponds to one target vector.
The optional parameters have the following interpretations.
options(1)
is set to 1 to display error values during training.
If options(1)
is set to 0,
then only warning messages are displayed. If options(1)
is -1,
then nothing is displayed.
options(2)
is a measure of the precision required for the value
of the weights w
at the solution.
options(3)
is a measure of the precision required of the objective
function at the solution. Both this and the previous condition must be
satisfied for termination.
options(5)
is set to 1 if an approximation to the Hessian (which assumes
that all outputs are independent) is used for softmax outputs. With the default
value of 0 the exact Hessian (which is more expensive to compute) is used.
options(14)
is the maximum number of iterations for the IRLS algorithm;
default 100.
glm
, glmerr
, glmgrad
Copyright (c) Ian T Nabney (1996-9)