Nathaniel, Of the two characteristics to which I pointed, I feel that the rectangularity check is the more important. I gave an example of a typo which demonstrated this problem. The error message reported that pinv does not have a conjugate function which, I suggest, is a totally misleading error message. In these circumstances, I hope that the Development Team will wish to treat this as a bug. Regards, Colin W. On 06-Jan-15 8:20 PM, Nathaniel Smith wrote:

Hi Colin,

On Wed, Jan 7, 2015 at 12:58 AM, cjw <cjw@ncf.ca> wrote:

My recollection, from discussions, at the time of the introduction of the @ operator, was that there was no intention to disturb the existing Matrix class. Yeah, we're not going to be making any major changes to the numpy.matrix class -- e.g. we certainly aren't going to disallow non-numeric data types at this point.

I see the matrix as a long recognized mathematical entity. On the other hand, the array is a very useful computational construct, used in a number of computer languages.

Since matrices are now part of some high school curricula, I urge that they be treated appropriately in Numpy. Further, I suggest that consideration be given to establishing V and VT sub-classes, to cover vectors and transposed vectors. The numpy devs don't really have the interest or the skills to create a great library for pedagogical use in high schools. If you're interested in an interface like this, then I'd suggest creating a new package focused specifically on that (which might use numpy internally). There's really no advantage in glomming this into numpy proper.

-n