FIND-MIN:  Find entry with minimum value (for cross validation)

Find-min reads of file of number pairs from standard input, determines
for which pair the second number is smallest, and writes the first
number of that pair (rounded to an integer) to standard output.

This is intended for use in cross-validation procedures.  For example,
suppose net-gd has been used to train a network by gradient descent,
with the results going to log-file.  We now wish to make predictions
for test cases using the network from this training session that has
the smallest error (minus log likelihood) on the validation data
stored in val-data.  We can do this as follows (on a Unix system):

  net-pred pa log-file `net-plt t L log-file / val-data . | find-min` 

The command in back-quotes finds the validation error for each
iteration, and find-min then selects the iteration with smallest
validation error.  This iteration number is substituted for the
command in back-quotes, thereby providing net-pred with the iteration
from log-file to be used.

            Copyright (c) 1995-2004 by Radford M. Neal