[R] How to ask for *fixed* number of distributions under parameterized Gaussian mixture model.

[Hung-Hsuan Chen (Sean)]

Dear R users:
I am wondering how to ask for *fixed* number of distributions under
parameterized Gaussian mixture model.

I know that em() and some related functions can predict the
parameterized Gaussian mixture model. However, there seems no
parameter to decide number of distributions to be mixed (if we known
the value in advance).

That is, assume I know the (mixed)data is from 3 different
distributions. The output, however, may indicate that number of
distributions that form the data is 4. How can I assign number of
distributions is 3 in advance?

Thanks a lot for your help.