5 Nov
2008
5 Nov
'08
9:29 a.m.
On Tue, Nov 4, 2008 at 11:05 PM, T J
On Tue, Nov 4, 2008 at 9:37 PM, Anne Archibald
wrote: 2008/11/5 Charles R Harris
: Hi All,
I'm thinking of adding some new ufuncs. Some possibilities are
expadd(a,b) = exp(a) + exp(b) -- For numbers stored as logs:
Surely this should be log(exp(a)+exp(b))? That would be extremely useful, yes.
+1
But shouldn't it be called 'logadd', for adding values which are stored as logs?
Hmm... but I'm thinking one has to be clever here because the main reason I heard for using logs was that normal floating point numbers had insufficient range. So maybe something like logadd(a,b) = a + log(1 + exp(b - a)) where a > b ? Chuck