Re: [sympy] Re: Help: simple univariate polynomial, sympy solve gives no results

2016-01-20 Thread Denis Akhiyarov
Oscar, you need to click on "more roots" in wolfram alpha to see the algebraic solution, which is definitely confusing. On Wednesday, January 20, 2016 at 3:55:37 AM UTC-6, Oscar wrote: > > On 20 January 2016 at 05:46, Denis Akhiyarov > wrote: > > On Tuesday, January 19,

Re: [sympy] Re: Help: simple univariate polynomial, sympy solve gives no results

2016-01-20 Thread Oscar Benjamin
On 20 January 2016 at 15:05, Denis Akhiyarov wrote: > > Oscar, you need to click on "more roots" in wolfram alpha to see the > algebraic solution, which is definitely confusing. Unless I'm misreading all of the additional roots are for the case where A=0. IOW Wolfram

Re: [sympy] Re: Help: simple univariate polynomial, sympy solve gives no results

2016-01-20 Thread Oscar Benjamin
On 20 January 2016 at 15:11, Aaron Meurer wrote: > SymPy has algorithms to find roots of quintics in radicals (when they > exist). I don't recall if the algorithms work for symbolic inputs. > > One can take a general quintic (x**5 + a*x**4 + b*x**3 + c*x**2 + d*x + e) > and

Re: [sympy] Re: Help: simple univariate polynomial, sympy solve gives no results

2016-01-20 Thread Aaron Meurer
On Wed, Jan 20, 2016 at 10:30 AM, Oscar Benjamin wrote: > On 20 January 2016 at 15:11, Aaron Meurer wrote: > > SymPy has algorithms to find roots of quintics in radicals (when they > > exist). I don't recall if the algorithms work for symbolic

Re: [sympy] Re: Help: simple univariate polynomial, sympy solve gives no results

2016-01-20 Thread Aaron Meurer
SymPy has algorithms to find roots of quintics in radicals (when they exist). I don't recall if the algorithms work for symbolic inputs. One can take a general quintic (x**5 + a*x**4 + b*x**3 + c*x**2 + d*x + e) and shift it by y (replace x with x - y). Then expand and collect terms in x. The

Re: [sympy] Re: Help: simple univariate polynomial, sympy solve gives no results

2016-01-20 Thread Denis Akhiyarov
I missed A=0 on wolfram, sorry for confusion On Wed, Jan 20, 2016, 9:38 AM Aaron Meurer wrote: > On Wed, Jan 20, 2016 at 10:30 AM, Oscar Benjamin < > oscar.j.benja...@gmail.com> wrote: > >> On 20 January 2016 at 15:11, Aaron Meurer wrote: >> > SymPy has

Re: [sympy] Re: Help: simple univariate polynomial, sympy solve gives no results

2016-01-20 Thread Aaron Meurer
WolframAlpha is solving for all five variables at once. The roots in radicals that it gives are when A = 0 (in which case, you have a quartic, which are solvable in radicals). Aaron Meurer On Wed, Jan 20, 2016 at 10:05 AM, Denis Akhiyarov wrote: > Oscar, you need to

[sympy] Re: Help: simple univariate polynomial, sympy solve gives no results

2016-01-20 Thread Kalevi Suominen
On Wednesday, January 20, 2016 at 4:37:18 AM UTC+2, Junwei Huang wrote: > > Hello, I am new to sympy and try to solve the following equation > > import sympy as sy > A,B,C,D,x=sy.var('A,B,C,D,x',positive=True) > sy.solve(A*x**5+B*x**4+C*x-D,x) > > but got no result. There are no roots, or I used

[sympy] It is possible to combine terms under a radical?

2016-01-20 Thread Jonathan Crall
I saw under http://docs.sympy.org/dev/tutorial/simplification.html#powsimp that it is impossible to combine radicals using powersimp: "This means that it will be impossible to undo this identity with powsimp(), because even if powsimp() were to put the bases together, they would be

Re: [sympy] Re: Manipulating expressions with vectors

2016-01-20 Thread Alex Lindsay
Looks neat. I will have to delve into it more. Thanks! On 01/16/2016 06:37 PM, brombo wrote: You may want to look at my geometric algebra module that uses sympy (github.com/brombo/galgebra) and see if it does what you want it to. I have attached the manual (galgebra.pdf) for you to look at.

Re: [sympy] Re: Manipulating expressions with vectors

2016-01-20 Thread Alex Lindsay
I like that :-) That's probably actually all I need for this case On 01/18/2016 10:36 AM, Francesco Bonazzi wrote: On Friday, 15 January 2016 17:04:20 UTC+1, Alexander Lindsay wrote: and carry them around in expressions that way because I want to *avoid* simplifications like (C is

Re: [sympy] Re: Help: simple univariate polynomial, sympy solve gives no results

2016-01-20 Thread Oscar Benjamin
On 20 January 2016 at 05:46, Denis Akhiyarov wrote: > On Tuesday, January 19, 2016 at 11:41:47 PM UTC-6, Denis Akhiyarov wrote: >> >> no algebraic roots according to this theorem: >> https://en.wikipedia.org/wiki/Abel%E2%80%93Ruffini_theorem The theorem only shows that