symbolic-math

Introduction to computer algebra systems? [closed]

浪子不回头ぞ 提交于 2019-12-03 01:43:24
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 . Does anybody know of any resources (books, classes, lecture notes, or anything) about the general theory of computer algebra systems (e.g. mathematica, sympy)? "Introductory" materials are preferred, but I realize that with such a specialized subject anything is bound to be fairly advanced. 回答1: "General Theory"

Extract complete argument and function name(s) from the Expression, (standard mathematical functions only) MAPLE

允我心安 提交于 2019-12-02 22:33:27
问题 For expressions like a1 := sin(1+a/b); a2 := log(1+ a*b); a3 := abs(a^2+b); how can I get expressions of respective functions. For example someCommand(a1) # should get an output 1+a/b someCommand(a2) # should get an output 1+a*b someCommand(a3) # should get an output a^2+b I have tried to get related topics from maple documentation but unfortunately am not able to get exactly. edited: Also how is it possible to get list (in sequence)of functions used let a :=sin(log(abs(a+b)));# functions can

How to find a function's rth derivative when r is symbolic in Mathematica?

回眸只為那壹抹淺笑 提交于 2019-12-02 22:00:50
I have a function f(t)=2/(2-t) . It is not so hard to get the rth derivative at t=0 (i.e. 2^(-r)*r! ) without using Mathematica. In the case of Mathematica calculation, I can get the r-th derivative when r=4 like this: D[2/(2-t), {t, 4}] . But how can I get the rth derivative at t=0 in Mathematica when r is ANY integer? I tried to use this expression, but it didn't work as expected: Simplify[D[2/(2 - t), {t, r}], Assumptions -> Element[r, Integers]] /. {t->0} Is it possible to do the above math symbolically in Mathematica just as we humans do? f = FindSequenceFunction[Table[D[2/(2 - t), {t, n}

Matlab Solve(): Not giving all the solutions

只愿长相守 提交于 2019-12-02 15:16:45
问题 I am trying to find intersection points of two curves syms x y g(x) = 20*(exp(-(x+30)/3.5)-1); [sol_x, sol_y] = solve((x+22.3097)^2+(y+16.2497)^2 == 25, y == g(x),x,y,'Real',true) ; It is giving only one solution. But according to the plot of the two equations, there should be two intersection points. How can I rectify this problem? 回答1: The solver can not find a analytic solution, thus a numeric solver is used. There is no reliable way in finding all solutions with a numeric method, but if

Introduction to computer algebra systems? [closed]

痴心易碎 提交于 2019-12-02 13:52:41
Does anybody know of any resources (books, classes, lecture notes, or anything) about the general theory of computer algebra systems (e.g. mathematica , sympy )? "Introductory" materials are preferred, but I realize that with such a specialized subject anything is bound to be fairly advanced. "General Theory" of CAS is a pretty huge scope for a question. That being said, I'll do my best to cover as much as I can in the hopes that something helps you find what you're looking for :) The proceedings of the ISSAC and SIGSAM groups would no doubt have some good stuff about techniques for building

Matlab Solve(): Not giving all the solutions

馋奶兔 提交于 2019-12-02 07:56:37
I am trying to find intersection points of two curves syms x y g(x) = 20*(exp(-(x+30)/3.5)-1); [sol_x, sol_y] = solve((x+22.3097)^2+(y+16.2497)^2 == 25, y == g(x),x,y,'Real',true) ; It is giving only one solution. But according to the plot of the two equations, there should be two intersection points. How can I rectify this problem? The solver can not find a analytic solution, thus a numeric solver is used. There is no reliable way in finding all solutions with a numeric method, but if you have a good guess (e.g. from a plot) try vpasolve with a reasonable set initial value. In this case, with

mtaylor MuPAD - Matlab

允我心安 提交于 2019-12-02 06:33:21
问题 I am trying to run the function mtaylor from the MuPAD engine in MatLab, which provides a multivariate Taylor expansion of a function. However, it keeps telling me I am trying to expand around an invalid point. Here is a minimal working example of what I tried: syms x y; feval(symengine,'mtaylor',exp(x^2 - y), [x, y], 4) Error message: vError using mupadengine/feval (line 157) MuPAD error: Error: Invalid expansion point. [mtaylor] Why doesn't this work? 回答1: The reason this works with MuPAD's

Laguerre polynomials in MATLAB

纵饮孤独 提交于 2019-12-02 03:46:23
I tried using the .. command in MATLAB to generate Laguerre polynomials but I keep getting this error every time: I found this in the help section: Since I have defined x as symbolic I shouldn't be getting this error. Also on website I found this which says that the function does not run in MATLAB. Can anyone help? Thanks in advance Like you say, and the matlab help says this function only works inside mupad, maybe in later versions it works in matlab console. If you want to use it, write mupad in Matlab Command window and then use it in the mupad, matlab will return you the result as I show

mtaylor MuPAD - Matlab

做~自己de王妃 提交于 2019-12-02 03:41:54
I am trying to run the function mtaylor from the MuPAD engine in MatLab, which provides a multivariate Taylor expansion of a function. However, it keeps telling me I am trying to expand around an invalid point. Here is a minimal working example of what I tried: syms x y; feval(symengine,'mtaylor',exp(x^2 - y), [x, y], 4) Error message: vError using mupadengine/feval (line 157) MuPAD error: Error: Invalid expansion point. [mtaylor] Why doesn't this work? The reason this works with MuPAD's mtaylor syms x y; feval(symengine,'mtaylor',exp(x^2 - y), x, 4) % [x] is fine too and this doesn't syms x y

Issue with Matlab solve function?

允我心安 提交于 2019-12-02 01:23:19
The following command syms x real; f = @(x) log(x^2)*exp(-1/(x^2)); fp(x) = diff(f(x),x); fpp(x) = diff(fp(x),x); and solve(fpp(x)>0,x,'Real',true) return the result solve([0.0 < (8.0*exp(-1.0/x^2))/x^4 - (2.0*exp(-1.0/x^2))/x^2 - (6.0*log(x^2)*exp(-1.0/x^2))/x^4 + (4.0*log(x^2)*exp(-1.0/x^2))/x^6], [x == RD_NINF..RD_INF]) which is not what I expect. The first question: Is it possible to force Matlab's solve to return the set of all solutions? (This is related to this question .) Moreover, when I try to solve the equation solve(fpp(x)==0,x,'Real',true) which returns ans = -1