[Numpy-discussion] users point of view and ufuncs

Robert Kern robert.kern at gmail.com
Fri Aug 25 13:02:10 CDT 2006


Charles R Harris wrote:

> Matrix rank has nothing to do with numpy rank. Numpy rank is simply the 
> number of indices required to address an element of an ndarray. I always 
> thought a better name for the Numpy rank would be dimensionality, but 
> like everything else one gets used to the numpy jargon, it only needs to 
> be defined someplace for what it is.

"numpy rank" derives from "tensor rank" rather than "matrix rank". It's not 
*wrong*, but as with many things in mathematics, the term is overloaded and can 
be confusing. "dimensionality" is no better. A "three-dimensional array" might 
be [1, 2, 3], not [[[1]]].

   http://mathworld.wolfram.com/TensorRank.html

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
  that is made terrible by our own mad attempt to interpret it as though it had
  an underlying truth."
   -- Umberto Eco





More information about the Numpy-discussion mailing list