[Numpy-discussion] Log Arrays

David Cournapeau cournape@gmail....
Thu May 8 11:52:19 CDT 2008


On Fri, May 9, 2008 at 1:25 AM, Charles R Harris
<charlesr.harris@gmail.com> wrote:
>

>
> But to expand on David's computation... If the numbers are stored without
> using logs, i.e., as the exponentials, then the sum is of the form:
>
> x_1*2**y_1 + ... + x_i*2**y_i

You missed the part on parametric models: in parametric settings, your
x_i are often exponential, so it makes sense to compute in the log
domain (you don't compute more log/exp than the naive implementation).

Of course, if we were not interested in log  x_i in the first place,
the thing would not have made any sense.

David


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