Log Message:
py-sympy: updated to 1.9

1.9

Highlights

The internal implementation of Matrix and other matrix classes (SparseMatrix \ 
etc) is now DomainMatrix. The ZZ and QQ domains are used for matrices with only \ 
integer or rational elements. Otherwise the new EXRAW domain is used. This \ 
should be backwards compatible although many internal methods and attributes are \ 
changed. At the time of this change the DomainMatrix routines are only used for \ 
addition and multiplication of matrices and some other simple low-level \ 
operations. Further changes will use DomainMatrix routines for operations like \ 
rref, det, lu etc and are expected to lead to big speedups for these \ 
computations. At this stage those big speedups are not realised but some basic \ 
operations such as indexing a matrix like M[0, 0] could potentially be slower. \ 
The new implementation can be much faster for most operations and is expected to \ 
lead to significant speed ups over the next few SymPy releases.

Leading term methods now raise PoleError at singularities. There was a \ 
long-standing issue of incorrect handling of leading term at singularities, \ 
where earlier, for compatibility reasons, the original expression itself was \ 
incorrectly returned. exp(1/x).as_leading_term(x) returned exp(1/x), but it does \ 
not have any leading term as x->0, so an error must be raised. Note that \ 
leadterm used to throw a ValueError even in the previous implementation as the \ 
original expression depends on the symbol x. A few examples of functions where \ 
this change would be visible - Pow, exp, log, factorial and gamma.