On Sat, Mar 20, 2010 at 2:00 PM, Charles R Harris charlesr.harris@gmail.com wrote:

Example,

Compute the qr factorization of a matrix.

Factor the matrix `a` as `qr`, where `q` is orthonormal (:math:`dot( q_{:,i}, q_{:,j}) = \delta_{ij}`, the Kronecker delta) and `r` is upper-triangular.

Arrggghhhh... Totally. Unreadable. Why not say the columns of q are orthonormal vectors and r is upper triangular? The math tutorial should go in the notes, if anywhere. Might mention that this is a 'thin' factorization (Golub). Let me propose a rule: no math markup in the summary, ever.

Parameters ---------- a : array_like, shape (M, N) Matrix to be factored. mode : {'full', 'r', 'economic'} Specifies the information to be returned. 'full' is the default. mode='r' returns a "true" `r`, while 'economic' returns a "polluted" `r` (albeit slightly faster; see Returns below).

Oh, come now, "true", "polluted"? Sounds a bit political... Actually, 'economic' contains info on the Householder reflections. In any case, why mention it at all, just refer to the return documentation. And wouldn't values be a better word than information?

Returns ------- * If mode = 'full':

* q : ndarray of float or complex, shape (M, K) * r : ndarray of float or complex, shape (K, N)

Size K = min(M, N)

* If mode = 'r':

* r : ndarray of float or complex, shape (K, N)

* If mode = 'economic':

* a2 : ndarray of float or complex, shape (M, N)

The diagonal and the upper triangle of a2 contains r, while the rest of the matrix is undefined.

WTF? I'm seeing stars.

As far as I know, stars are the only way to render a list in restructured txt, otherwise it looses the list formatting. I tried several versions, but never found a different way. (I don't remember whether the empty lines are strictly necessary in sphinx docs, but they are in rst.)

But, the markup creates nice hml and htmlhelp docs, and it can be published as pdf.

Josef

I may be old and crotchety, and I don't mean to be mean to the folks who have done the hard work to bring the docstring to its current state, but I think things have gotten out of hand.

Chuck

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