JuliaLang/julia — Issue #272: separate LU economy mode
Author: JeffBezanson
Created: 2011-12-01 03:04:21+00:00
State: open
Labels: performance

Currently we can't infer a simple type for the result of `lu` since it might return either (LU, P) or (L, U, P).
I'm willing to give in on this in some cases, but this one doesn't seem necessary. Especially since `lu(A, true)` is not very easy to read. Yes, a keyword argument would be best but that still probably won't fix the type issue.
We need something like `lu_compact` or `lu_econ`.

Similar concerns might apply to other linear algebra functions. But it's much better if the various possible returns are prefixes of each other, i.e. `(A,B)`, `(A,B,C)`, `(A,B,C,D)` etc. so we always know the types of values that are requested.