computer-algebra-systems

问题 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 4 years ago . 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

问题 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 4 years ago . 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

问题 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 4 years ago . 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

问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 4 years ago . I am looking for C++ open-source library (or just open-source Unix tool) to do: Equality test on Equations . Equations can be build during runtime as AST Trees, string or other format. Equations will mostly be simple algebra ones, with some assumptions about unknown functions. Domain, will be integer arithmetic

问题 I convert list to matrix in Maxima in following way: DataL : [ [1,2], [2,4], [3,6], [4,8] ]; DataM: apply('matrix,DataL); How to do it the other way ? How to convert given matrix DataM into list DataL ? 回答1: I know it's late in the game, but for what it's worth, there is a simpler way. my_matrix : matrix ([a, b, c], [d, e, f]); my_list : args (my_matrix); => [[a, b, c], [d, e, f]] 回答2: I'm far from a Maxima expert, but since you asked me to look at this question, here's what I have after a

问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 2 years ago . I am trying to implement a graphing calculator on the iPhone. I am looking for a library that can take strings of expressions or functions and let me manipulate them (find derivatives, intercepts, zeros, etc). Does anything like this exist? 回答1: There's GiNaC for C++. GPL-licensed and actively maintained, last

问题 I have systems of polynomials, fairly simple polynomial expressions but rather long to optimize my hand. Expressions are grouped in sets, and in a given set there are common terms in several variables. I would like to know if there is a computer algebra system, such as Mathematica, Matlab, or sympy, which can optimize multiple polynomials with common terms to minimize number of operations. It would be also great if such system can minimize the number of intermediate terms to reduce number of

问题 I want to write an (somehow) enhanced sum function which takes a number of indices at once, but I cannot understand how to get it work. Here is what I currently have: (%i1) nsum(indexes, expr) := if indexes = [] then expr else nsum(rest(indexes), sum(expr, first(indexes),1, N)) $ (%i2) nsum([i,j], i+j), nouns; sum: index must be a symbol; found intosym(first(indexes)) #0: nsum(indexes=[k,j],expr=k+j) I think this could be fixed by forcing Maxima expand first(indexes) into a symbol before

问题 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

问题 Using Sympy, say we have an expression f, which is a polynomial of the Symbol "x" (and of potentially other symbols). I would like to know what if there is an efficient way to drop all terms in f of order greater than some integer n. As a special case I have a very complicated function but i want to only keep terms up to 2nd order in x. What's the efficient way to do this? The obvious, not-very-efficient way to do it would be for each m less than n, take m derivatives and set x to 0 to obtain