On Thursday, November 13, 2014 10:34:14 AM UTC-5, Stefan Karpinski wrote: > > The frequency of people having these nearly symmetric (nearly Hermitian, > etc.) matrices that they generated suggest to me that it would be nice to > be able to apply the Symmetric wrapper to force symmetry (already works), > but that we may want to consider the true symmetrized value to be the > average of the two sides or something like that – after all, we have no > real reason to choose the top or bottom half as correct. >
Another reason to have a function for this is that computing sym(A) = (A + A')/2 is quite a common operation in linear algebra, closely analogous to real(z). The other common operation is to take the antisymmetric part (A - A')/2 or the "imaginary" part (A - A')/(2im) [which has the advantage of being Hermitian, but the disadvantage of being complex even if A was real]. Maybe we should have functions realm(A) and imagm(A)?
