On Mon, Aug 22, 2011 at 1:27 PM, Phil Steitz <phil.steitz@gmail.com> wrote:
> I think it would be good to add this, but it would probably be
> better to give it a different name. What name, I am not sure.
> Maybe setAll or fill. Might also be useful to have versions that
> fill submatrics.
>
Mahout allows this via overloading of an assign method.
Matrix.assign(double) overwrites all cells with a constant value.
Matrix.assign(Matrix) copies data into the target. x.assign(Matrix y,
BinaryFunction f) does elementwise x_ij = f(x_ij, y_ij)
> Here is a little joke to lighten things up a bit. What if we just
> allow people to specify negative indices to mean "everything." So
> for example, setEntry(1, 1, 0) sets all entries to 0, setEntry(1,
> 1, 0) sets the first row to 0. Just kidding ;)
>
Can be useful.
I find the TCL convention more useful where 1 refers to the last element of
a vector.
This sort of thing does tend to freak out the more mathematically inclined
and it does make it harder to catch errors in mathematical code since it
mutes indexing errors.
