Re: Bizarre semantic of Mat

[Loïc Grenié <loic.grenie@gmail.com>]

On Wed Jan 17th, 2024, at 11:31, Bill wrote:

On Tue, Jan 16, 2024 at 06:36:52PM -0800, Ilya Zakharevich wrote:
> Today I (finally) looked through the documentation of Mat() — and it
> seems to be very convenient for interactive usage!  On the other hand,
> such “cute” semantics have a tendency to become a limiting factor when
> one wants to write down general-purpose algorithms…
>
> Is there a simple way to convert a vector-column into a 1 column
> matrix (without using matrix())?  Mat() is almost there — except for
> bizarre special-cases — which are impossible to switch off!

There is a trick:

? V=[[1]~,[2]~,[3]~]
%28 = [[1]~,[2]~,[3]~]
? Mat(V~)~
%29 = Mat([[1]~,[2]~,[3]~])
? V=[[1],[2],[3]]~
%30 = [[1],[2],[3]]~
? Mat(V~)~
%31 = [[1];[2];[3]]

? V=[[1]~,[2]~,[3]~]
%28 = [[1]~,[2]~,[3]~]

? Mat(concat(V))

%29 =

[1]

[2]

[3]

     Loïc