From: hinsen at cnrs-orleans.fr (Konrad Hinsen) Date: 09 Apr 1999 20:10:52 +0200 Subject: Numeric: vector operations? References: Message-ID: Content-Length: 1517 X-UID: 385 Joe Strout writes: > Playing with Numeric today, I noticed an apparent lack of common vector > operations, like normalization, vector-length, and cross product. If you mean vectors as in 3D geometry, look at the module Vector in my collection of scientific modules (http://starship.python.net/crew/hinsen/scientific.html). For vectors in the sense of rank-one arrays, I am not aware of any available module that contains these operations (and the cross product is limited to 3D-space anyway), but they are also much less frequently needed for non-geometric work. > These are fairly easy to code for my own evil purposes, but it's > surprising that they're not in there. Am I missing something? Or are > they purposefully omitted for some reason (e.g., they only apply to > very restricted sorts of matrices whereas other operations are more > general)? I guess there is too little advantage in writing Numeric.vector_length(v) over Numeric.sqrt(Numeric.add.reduce(v**2)) -- ------------------------------------------------------------------------------- Konrad Hinsen | E-Mail: hinsen at cnrs-orleans.fr Centre de Biophysique Moleculaire (CNRS) | Tel.: +33-2.38.25.55.69 Rue Charles Sadron | Fax: +33-2.38.63.15.17 45071 Orleans Cedex 2 | Deutsch/Esperanto/English/ France | Nederlands/Francais -------------------------------------------------------------------------------