# computer-algebra-systems

##### C# library for algebra simplification and solving [closed]

Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 5 years ago. Improve this question There are quite a few algebra solvers and simplifiers on the web (for example, the decent one at algebra.com). However, I'm looking for something I can plug into C# as part of a larger project (I'm making my own calculator, but obviously I'd ask permission etc.). Ideally, I'd use code like: String s = MathLib.Simplify("5x*(500/x^2*(sqrt(3)/4)+1)+2x^2+(sqrt(3)/2)*x^2

2021-05-17 18:13:12    分类:问答    c#   algebra   symbolic-math   computer-algebra-systems

##### How to do function composition in Sympy?

I want to do something like h = f(g(x)) and be able to differentiate h, like h.diff(x). For just one function like h = cos(x) this is in fact possible and the documentation makes it clear. But for function compositions it is not so clear. If you have done this, kindly show me an example or link me to the relevant document. (If Sympy can't do this, do you know of any other packages that does this, even if it is non-python) thank you.

2021-05-08 21:52:24    分类:问答    python   sympy   computer-algebra-systems

##### Dealing with piecewise equations returned by sympy integrate

In sympy I have an integral which returns a Piecewise object, e.g. In [2]: from sympy.abc import x,y,z In [3]: test = exp(-x**2/z**2) In [4]: itest = integrate(test,(x,0,oo)) In [5]: itest Out[5]: ⎧ ___ ⎪ ╲╱ π ⋅z │ ⎛ 1 ⎞│ π ⎪ ─────── for │periodic_argument⎜──────────────, ∞⎟│ ≤ ─ ⎪ 2 │ ⎜ 2 ⎟│ 2 ⎪ │ ⎝polar_lift (z) ⎠│ ⎪ ⎪∞ ⎪⌠ ⎨⎮ 2 ⎪⎮ -x ⎪⎮ ─── ⎪⎮ 2 ⎪⎮ z ⎪⎮ ℯ dx otherwise ⎪⌡ ⎪0 ⎩ I would like to extract just the first branch of this piecewise equation, in other words, I would like to be able to do something like itest.parts(0)to extract simply sqrt(pi)*z/2. I can't seem to find any way to do

2021-05-01 04:21:07    分类:问答    python   sympy   symbolic-math   computer-algebra-systems   symbolic-computation

##### 符号代数表达式的符号(Sign of a symbolic algebraic expression)

2021-04-29 16:02:23    分类:技术分享    algorithm   algebra   computer-algebra-systems

##### Multivariate Taylor approximation in sympy

I aim to write a multidimensional Taylor approximation using sympy, which uses as many builtin code as possible, computes the truncated Taylor approximation of a given function of two variables returns the result without the Big-O-remainder term, as e.g. in sin(x)=x - x**3/6 + O(x**4). Here is what I tryed so far: Approach 1 Naively, one could just combine the series command twice for each variable, which unfortunately does not work, as this example shows for the function sin(x*cos(y)): sp.sin(x*sp.cos(y)).series(x,x0=0,n=3).series(y,x0=0,n=3) >>> NotImplementedError: not sure of order of O(y*

2021-04-29 14:12:27    分类:问答    python   sympy   computer-algebra-systems   symbolic-computation

##### Haskell library like SymPy? [closed]

Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 6 years ago. Improve this question I need to manipulate expressions like 1 + sqrt(3) and do basic arithmetic like addition, subtraction, and division. I'd like the result to be in some sort of canonical form so that it can be used as a key in a map. Turning 1 + sqrt(3) into a float is not feasible due to roundoff problems. I used SymPy for this task in Python. Is there an equivalent native library

2021-04-23 06:38:26    分类:问答    haskell   symbolic-math   computer-algebra-systems

##### Sign of a symbolic algebraic expression

Is there any algorithm that can find the sign of an arbitrary symbolic algebraic expression given in a "Tree - Form"? I know that a general algorithm doesn't exist because the zero recognizion problem is undecidable for an arbitrary expression, but how should I approach the problem of finding the sign of an expression? (how is this done in computer algebra?) For example: sign(sqrt(2)-1) = ?

2021-04-05 03:16:56    分类:问答    algorithm   algebra   computer-algebra-systems