# [PYTHON MATRIX-SIG] logical_or and logical_and and # of arguments

**Jim Hugunin
**
hugunin@mit.edu

*Wed, 19 Mar 1997 15:33:05 -0500*

David Ascher writes:
...
>* Either logical_or can deal with a large number of arguments or it can't
*--
>* if it can't, what does the 3-argument version mean?
*
logical_or is a binary function (it takes two arguments). As with all
umath functions, it will take an optional extra argument to specify a
preexisting array to hold the result of the computation.
All of the umath "functions" (actually they're objects) have a reduce
method as well. This method provides an easy way to get the behavior
you're looking for, ie.
logical_or.reduce( [x1,x2,x3,...,xn] )
will give you what you want. In fact, this is useful often enough that
there's a function for it called "sometrue" which is exactly equal to
logical_or.reduce.
Note: x1, ..., xn must have the same shapes for this to work. If this is
not true, then you'll need to use a combination of binary logical_or's.
-Jim
_______________
MATRIX-SIG - SIG on Matrix Math for Python
send messages to: matrix-sig@python.org
administrivia to: matrix-sig-request@python.org
_______________