Stream: math-comp users

Topic: representation of a vector in terms of basis

Mohit Tekriwal (Jan 28 2022 at 23:28):

Hi, I am looking for a lemma in mathcomp matrix libraries that allow me to express a vector in terms of a given set of basis vectors. Could someone please point me to the specific lemma that talks about such representation ? Thanks a lot ! :)

Cyril Cohen (Jan 29 2022 at 15:26):

Well, there is no "lemma" per se for that, since if you have a basis expressed as a square matrix P where each row represents a vector of the basis, and if you have a vector v you want to reexpress in this basis, you only need to do v * P^-1to get an row vector which represents the expression of v in the basis P.

Mohit Tekriwal (Jan 29 2022 at 17:22):

Thanks Cyril ! I will try that.

Karl Palmskog (Jan 29 2022 at 17:31):

is this really a MathComp analysis specific question? To me, it sounds like a general MathComp question (since basis vectors need not be of real numbers...)

Mohit Tekriwal (Jan 29 2022 at 19:26):

yeah, it's a general Mathcomp question

Notification Bot (Jan 29 2022 at 19:39):

This topic was moved here from #math-comp analysis > representation of a vector in terms of basis by Karl Palmskog

Last updated: Jan 29 2023 at 19:02 UTC