Towards a new SymPy
oscarbenjamin.github.io
Towards a new SymPy
1–10 of 72 posts
Re: Towards a new SymPy
#2I love SymPy. Its so useful for doing calculations I don't want to do myself.
Re: Towards a new SymPy
#3The unfortunate thing is that core CAS functionality (and performance) should be based on a SAT/SMT engine to discover the rewrite rules and it goes without saying (but I'll say it anyway) implementing that is "hard". Naively (i.e., I haven't really thought through it), I think sympy should be built on top of z3 or cvc5 or at least very tighly integrated (e.g., support as a backend). And (again naively) I think until such time, sympy will remain a toy.
I will say though that symengine is a great project and congrats to that guy for pulling it off under the constraints of a phd.
Re: Towards a new SymPy
#4The unfortunate thing is that core CAS functionality (and performance) should be based on a SAT/SMT engine to discover the rewrite rules and it goes without saying (but I'll say it anyway) implementing that is "hard". Naively (i.e., I haven't really thought through it), I think sympy should be built on top of z3 or cvc5 or at least very tighly integrated (e.g., support as a backend). And (again naively) I think until…
Not an expert in SAT solvers, personally. What would the benefit be in using one?
Anaconda's absurdly slow dependency resolver (it takes up to 15 minutes for things Pip installs in seconds, with no way of disabling it outside of installing a third party solver) is based on SAT and left a bad taste in my mouth for them (slow, clunky, etc), but maybe it's just a poor implementation on their part.
Re: Towards a new SymPy
#5I really liked the article and how it explained CAS vs Numerical solutions.
It also looks like SymPy or SymEngine is starting to catch up to Mathematica which also is pretty cool and does the same kind of expansion of an expression into a tree of sub expressions.
Re: Towards a new SymPy
#6Part II made the front page yesterday: https://news.ycombinator.com/item?id=37426080
A comment there makes what I think is a very good point about "the lack of consolidation of computer algebra efforts": https://news.ycombinator.com/item?id=37430437
I don't know what might drive or foster such consolidation. Maybe Category Theory? Bridging syntax?
Re: Towards a new SymPy
#7SymPy is pretty nice but every time I use it for a real problem I end up hitting a wall and have to dig through the source or look at old issue reports for a workaround.
Most recently I wanted to simplify a complex expression with terms like ‘diag(v1) * v2’ into Hadamard products, and found I’d need to implement custom rules to get it to work.
Re: Towards a new SymPy
#8The unfortunate thing is that core CAS functionality (and performance) should be based on a SAT/SMT engine to discover the rewrite rules and it goes without saying (but I'll say it anyway) implementing that is "hard". Naively (i.e., I haven't really thought through it), I think sympy should be built on top of z3 or cvc5 or at least very tighly integrated (e.g., support as a backend). And (again naively) I think until…
Is Mathematica built like this?
Re: Towards a new SymPy
#9Regarding the issue of representing symbolic expression and controlling their evaluation or simplification, are there precedents of using e-graphs to memoize and reuse work rather than simple trees with destructive updates?
Re: Towards a new SymPy
#10I really liked the article and how it explained CAS vs Numerical solutions. It also looks like SymPy or SymEngine is starting to catch up to Mathematica which also is pretty cool and does the same kind of expansion of an expression into a tree of sub expressions.
Is there any comparison of their features anywhere? Last time I tried sympy a few years ago, it was quite a bit lacking compared to Mathematica.