Determinants

[translunar]

Matrix determinants!

It'd be nice to have two varieties: exact and fast. For 2x2 and 3x3, only exact will be used, unless the user requests an exact determinant of some larger matrix (which should thus be available, unless sufficient accuracy can be achieved with a faster algorithm).

As the matrices increase in size, there will eventually be a crossover point where we go from the exact method to the fast approximation.

Determinant is a fairly important calculation, so it'd be great if it were implemented for dense and yale. Dense is obviously priority 1.

[translunar]

2x2 and 3x3 exact determinants added.

[atimin]

Sorry, if I are seeming a ignoramus.. exact method is a calculation determinant by сofactors, isn't it? Then fast algorithm is unknown for me. Could you publish link to description this algorithm?

[translunar]

I think it requires some research. If I knew the answer, it'd be much easier to implement.

http://en.wikipedia.org/wiki/Determinant#Calculation

That gives you a few places to start, particularly under "Further methods," but I think you may need to do some reading.

[translunar]

This issue now duplicates #47.