vector manipulations

Your problem is that your function log1( , ) is not vectorized with
respect to its arguments.  For a function to work in outer(...) it must
accept vectors for its first two arguments and it must produce a
parallel vector of responses.  

To quote the help information for outer:

"FUN is called with these two extended vectors as arguments. Therefore,
it must be a vectorized function (or the name of one), expecting at
least two arguments."

Sometimes Vectorize can be used to make a non-vectorized function into a
vectorized one, but the results are not always entirely satisfactory in
my experience.