MIX-GEN:  Generate hyperparameters randomly from the prior, or fix them.

Mix-gen writes a series of independently-generated values for the 
hyperparameters of a mixture model to a log file.


    mix-gen log-file [ max-index ] [ "fix" [ SD-value ] ]

Records of hyperparameters with indexes from zero up to the indicated
index are generated (the default is max-index of zero).  If the log
file already contains records with some of these indexes, only records
with indexes greater than the last existing record are generated.

If just max-index is specified, the hyperparameters are generated
randomly from the prior, using the random number seed taken from the
log file (eg, as specified by rand-seed).

The "fix" option is useful for initializing iterative programs.  If it
is given, the variable hyperparameters are not generated at random,
but are instead set to fixed values.  The mean parameters will be
fixed to zero.  The standard deviation hyperparameters will be fixed
to the value given after "fix", or at the location parameter of their
prior distribution, if no such value is specified.

No data model is required to use mix-gen, but if a model is specified,
the hyperparameters associated with it are generated as well.

Note that mix-gen does not generate values for the parameters
associated with particular mixture components.

            Copyright (c) 1997 by Radford M. Neal