- Update to version 9.200.7:
+ Misc bug fixes.

- Update to version 9.200.4:
+ Faster handling of symmetric positive definite matrices by
rcond().
+ Faster transpose of matrices with size ≥ 512x512.
+ Faster handling of compound sparse matrix expressions by
accu(), diagmat(), trace().
+ Faster handling of sparse matrices by join_rows().
+ Added sinc().
+ Expanded sign() to handle scalar arguments.
+ Expanded operators (*, %, +, −) to handle sparse matrices with
differing element types (eg. multiplication of complex matrix
by real matrix).
+ Expanded conv_to() to allow conversion between sparse matrices
with differing element types.
+ Expanded solve() to optionally allow keeping solutions of
systems singular to working precision.

- Update to version 9.100.5:
+ Faster handling of symmetric/hermitian positive definite
matrices by solve().
+ Faster handling of inv_sympd() in compound expressions.
+ Added .is_symmetric().
+ Added .is_hermitian().
+ Expanded spsolve() to optionally allow keeping solutions of
systems singular to working precision.
+ New configuration options ARMA_OPTIMISE_SOLVE_BAND and
ARMA_OPTIMISE_SOLVE_SYMPD.