Influence of `anorm` on performance of `expmv` and `phimv`?

[GiggleLiu]

In PR #30 , we find the variable anorm = norm(A, Inf) in expmv function does not affect the correctness and performance of the program.

As norm function is not designed for a general Linear Operator, it is natural to ask what it is used for and whether it should be required?

[garrison]

Should this be considered to be resolved with the merging of #30, or is the goal to do additional benchmarks/tests here to better understand this issue?

[acroy]

I would like to figure out what anorm does hence I asked @GiggleLiu to open this issue.