How can I construct matrices over the octonions?
Using QuaternionAlgebra, I can make and multiply matrices with quaternionic entries without difficulty. Using OctonionAlgebra, if I try to make a matrix I get a type error telling me that my algebra is not a ring. So far as I can track it down, Matrix_Spaces runs a test asking whether the algebra is in Rings. QuaternionAlgebras are; OctonionAlgebras are not.
Is there a reasonable way to work around this issue? Manually add my octonion algebra to Rings? Disable the type check in Matrix_Spaces?? Something else?
I suggest to report this issue at https://github.com/sagemath/sage/issues
Octonions not being associative, matrices make no sense.
Which operations are needed for these matrices over the octonions? Just make an own class if the wanted mathematical application is a short (or not involved) project...
@FrédéricC & @dan_fulea: Matrix multiplication requires only multiplication and addition, which are already defined. But I don't know enough Sage/Python to bypass the test in Matrix_Spaces which is preventing matrix computations using existing operations. @Max Alekseyev: Will do; thanks for the suggestion.