# SymPy 0.5.13¶

6 Mar 2008

- SymPy is now 2x faster in average compared to the previous release
- first patches with 25% speedup
`Basic.cos`

et. al. removed, use`C.cos`

instead`sympy.core`

now uses direct imports`sympifyit`

decorator- speedup Integers creation and arithmetic
- speedup unary operations for singleton numbers
- remove silly slowdowns from fast-path of mul and div
- significant speedup was achieved by reusing dummy variables
`is_dummy`

is not an assumption anymore- Symbols & Wilds are cached
`((2+3*I)**1000).expand()`

is now at least 100x faster`.expand()`

was made faster for cases where an expression is already expanded- rational powers of integers are now computed more efficiently
- unknown assumptions are now cached as well as known assumptions

`integrate()`

can handle most of the basic integrals now- interactive experience with isympy was improved through adding support for , () and {} to pretty-printer, and switching to it as the default ipython printer
- new
`trim()`

function to map all non-atomic expressions, ie. functions, derivatives and more complex objects, to symbols and remove common factors from numerator and denominator. also cancel() was improved `.expand()`

for noncommutative symbols fixed- bug in
`(x+y+sin(x)).as_independent()`

fixed `.subs_dict()`

improved- support for plotting geometry objects added
- bug in
`.tangent_line()`

of ellipse fixed - new atan2 function and assotiated fixes for
`.arg()`

and expanding rational powers - new
`.coeff()`

method for returning coefficient of a poly - pretty-printer now uses unicode by default
- recognition of geometric sums were generalized
`.is_positive`

and`.is_negative`

now fallback to`evalf()`

when appropriate- as the result
`oo*(pi-1)`

now correctly simplifies to oo - support for objects which provide
`__int__`

method was added - we finally started SymPy User’s Guide
`BasicMeths`

merged into`Basic`

- cache subsystem was cleaned up – now it supports only immutable objects