Re: [sage-support] Re: solve and numerical answers

On Tuesday, September 15, 2020 at 3:20:13 PM UTC-4 Emmanuel Charpentier wrote: > sage: L[1].n() > > fails because L1 is an equation, i. e a symbolic expression whose operator > is the built-in “eq”, which has no n() method. > > However, > > sage: PP=-625/1000*t^4 + 2355/100*t^3 -

Re: [sage-support] Re: solve and numerical answers

sage: L[1].n() fails because L1 is an equation, i. e a symbolic expression whose operator is the built-in “eq”, which has no n() method. However, sage: PP=-625/1000*t^4 + 2355/100*t^3 - 264051/1000*t^2 + 10269/10*t - 8538/10 sage: PP.parent() Symbolic Ring sage: L=solve(PP,t) sage:

Re: [sage-support] Re: solve and numerical answers

Thanks! I've already learned more. What I first did was this: sage: PP -0.625*t^4 + 23.55000*t^3 - 264.0510*t^2 + 1026.900*t - 853.8000 sage: L=solve(PP==0,t) sage: L[1] t == -1/1250*sqrt((390625*(4/1953125*I*sqrt(37468876945450884598)*sqrt(5) -

[sage-support] Re: solve and numerical answers

> I still don't know my way around the Sage documentation... Sorry for the > elementary question. > > Yeah, we are sorry that it never has gotten more organized (though it is actually quite thorough!). You may want to try the French (now in English) Sage book, or Greg Bard's AMS (but free

[sage-support] Re: Solve this Equation for H: 5260862 = M*H^y % 20876441; know variables y and M.

H = (Mod(20192834, 20876441)^-1 * 5260862).nth_root(17) On Thursday, May 14, 2020 at 3:26:09 PM UTC+2, Madison Adams wrote: > > Solve this Equation for H: 5260862 = M*H^y % 20876441 > > Does anyone happen to know the steps to solve for h: > Equation: 5260862 = M*Hy % 20876441 > > Where y = 17,

[sage-support] Re: Solve inequality in Sage

Have you had a look at https://doc.sagemath.org/html/en/reference/numerical/sage/numerical/mip.html? Seems to be what you want to do essentially. julian On Sunday, October 20, 2019 at 5:34:37 PM UTC+2, Santanu wrote: > > Hi, > I have inequalities like these: > > 3 x1 + 5 x2 + 2 x3 + 5 x4 + 7

Re: [sage-support] Re: Solve equation efficiently

On Tue, 30 Jul 2019 at 05:56, Kwankyu wrote: > > > On Thursday, July 25, 2019 at 12:08:20 AM UTC+9, chandra chowdhury wrote: >> >> I have matrices B and C of size (m,n) over integer with m>n. >> I know there is matrix A of size (m,m) such that >> AB=C. How to find A efficiently in Sage? >> > Try

[sage-support] Re: Solve equation efficiently

On Thursday, July 25, 2019 at 12:08:20 AM UTC+9, chandra chowdhury wrote: > > I have matrices B and C of size (m,n) over integer with m>n. > I know there is matrix A of size (m,m) such that > AB=C. How to find A efficiently in Sage? > I guess there is no special way in Sage to solve your kind

[sage-support] Re: solve() behavior

after solving an equation (or not) for x, I can check if the answer still contains x by ans.has(x). That should weed out any non-explicit solutions. But still: am I guaranteed for any class of equations, e.g. polynomial equations of degree <= 4, that if solve produces an empty list there

[sage-support] Re: solve() behavior

On Tuesday, February 19, 2019 at 8:56:50 AM UTC-8, Michael Beeson wrote: > > When I try to reproduce Eric's post, I get an error message about an > unexpected keyword argument > (maybe my version of Sage is too old.) But look at this: > > sage:

[sage-support] Re: solve() behavior

When I try to reproduce Eric's post, I get an error message about an unexpected keyword argument (maybe my version of Sage is too old.) But look at this: sage: solve(*2**(x+sqrt(*1*-x^*2*))-*7*,x,explicit_solutions=True) [1/4*I*sqrt(41) + 7/4 == -1/2*sqrt(7/2*I*sqrt(41) + 2), 1/4*I*sqrt(41)

[sage-support] Re: solve() behavior

Eric's post shows me how to get that particular example solved. But my real concern is, when my code (inside some deep loop) calls solve, I want to know (a) if it returns an answer, that answer really is a solution, and (b) if it returns an empty list, there really is no solution.

[sage-support] Re: solve() behavior

Hi, Le lundi 18 février 2019 21:56:56 UTC+1, Michael Beeson a écrit : > > sage: solve(*2**(x+sqrt(*1*-x^*2*))-*7*,x) > > [x == -sqrt(-x^2 + 1) + 7/2] > > > sage: version() > > 'SageMath version 8.0, Release Date: 2017-07-21' > > > That doesn't look like a solution to me because x still appears

[sage-support] Re: solve

yes exactly what I wanted. Sorry again for the bad explanation of my problem, by the way I hadn't found the wiki you gave the link Thanks Henri Le vendredi 5 octobre 2018 13:05:06 UTC+2, HG a écrit : > > I would like to solve these equations but I don't know how? > > > >

[sage-support] Re: solve

It seems you want to revert the Lorentz transformation: https://en.wikipedia.org/wiki/Lorentz_factor#Occurrence In this case you have a system of equations relating the various quantities c, ga, t, tt, x, xx, v, where - ga is the gamma factor, c is the speed of light, - v is the relative speed

[sage-support] Re: solve

sorry for the bazar ! I don't know how to make latex in the mail I will make it with sage Le vendredi 5 octobre 2018 13:05:06 UTC+2, HG a écrit : > > I would like to solve these equations but I don't know how? > > > > t_0=t_p==gamma*(t-V*x/c^2);show(t_0) > > x_0=x_p==gamma*(x-V*t);show(x_0) > >

[sage-support] Re: solve

Sorry for not being clear :) I wonder if I can calculate x'′=γ(x−vt) t′=γ(t−vxc2) γ=11√−v2c2 Le vendredi 5 octobre 2018 13:05:06 UTC+2, HG a écrit : > > I would like to solve these equations but I don't know how? > > > > t'=gamma*(t-vx/c^2);show(t') > > x'=gamma*(x-v*t);show(x') > > > >

[sage-support] Re: solve /desolve

On Wed 2018-10-03, 18:34:51 UTC+2, HG wrote: > I would like to solve these equations but I don't know how? > > t_0=t_p==gamma*(t-V*x/c^2);show(t_0) > x_0=x_p==gamma*(x-V*t);show(x_0) > > solve(t_0,gamma*(t-V*x/c^2)) > desolve(gamma*(t-V*x/c^2)==0,x) > > error desolve() takes at least 2 arguments

[sage-support] Re: solve() determines incorrect number of roots

You are doing inexact computations, and imaginary errors creep in. Indeed, let's first run without assume()'s: sage: s=solve(f(x) == 0,x) sage: [t.rhs().n() for t in s] [0.464973569257452 - 1.11022302462516e-16*I, 0.0267727617252126 + 1.11022302462516e-16*I, 2.00825366901734] so you see a

[sage-support] Re: Solve gives incorrect solutions for polynomial

> > > > Interesting. If you have ideas on how to improve it so that you might > do > > so, please start a thread on sage-devel about that. > > I don't. I have expressed my dislike of AskSage as soon as it was > available. It is just that I don't like all these badges and awards and > I

Re: [sage-support] Re: Solve gives incorrect solutions for polynomial

Sage has two sources of support, the mailing list sage-support and the AskSage site. Users and helpful developers can use whichever they choose, and I don't think that any of us should be telling anyone which one they ought to use, either as an asker of questions or as a helpful answerer. Of

[sage-support] Re: Solve gives incorrect solutions for polynomial

Hi Karl-Dieter, On 2016-11-09, kcrisman wrote: >> > This is a very good question for Ask Sage, would you ask it there? >> >> Why should he? He did ask here. And I, for one, dislike the Ask Sage >> pages to the extent that I wouldn't answer questions there. >> > >

[sage-support] Re: Solve gives incorrect solutions for polynomial

> > This is a very good question for Ask Sage, would you ask it there? > > Why should he? He did ask here. And I, for one, dislike the Ask Sage > pages to the extent that I wouldn't answer questions there. > Interesting. If you have ideas on how to improve it so that you might do so,

[sage-support] Re: Solve gives incorrect solutions for polynomial

A bit of numerical analysis (see enclosed Jupyter notebook) proves that this polynomial has at least two real roots, and quite probably four), one of them being positive. This triggers the question : does Sage have built-in facilities for uncertainty computation ("calcul d'erreurs" in French,

[sage-support] Re: Solve gives incorrect solutions for polynomial

On 2016-11-08, slelievre wrote: > This is a very good question for Ask Sage, would you ask it there? Why should he? He did ask here. And I, for one, dislike the Ask Sage pages to the extent that I wouldn't answer questions there. Cheers, Simon -- You received this

[sage-support] Re: Solve gives incorrect solutions for polynomial

Sun 2016-11-06 16:00:30 UTC+1, Francis Banks: > I am solving a polynomial which arises from plotting titration cures > in chemistry. The rule of signs suggests it has one positive root. > Find_root seems to find it. Solve with poly_solve=true does not. > Instead it gives 4 complex roots, which

[sage-support] Re: Solve gives incorrect solutions for polynomial

On Sunday, November 6, 2016 at 3:00:30 PM UTC, Francis Banks wrote: > > I am solving a polynomial which arises from plotting titration cures in > chemistry. The rule of signs suggests it has one positive root. Find_root > seems to find it. Solve with poly_solve=true does not. Instead it gives

[sage-support] Re: solve(-(1/2*sqrt((4*w+1)+1))*t+w==0,w)

thank you, Simon many computational aspects, but still human insight is needed to break a problem up into sub-problems of chewable size, or transform the original problem into one that is more accessible to automatic solutions. And even if a computer algebra system (no matter which one)

[sage-support] Re: solve(-(1/2*sqrt((4*w+1)+1))*t+w==0,w)

In fact, the solution is: w=t+t^2 Are you sure? Assuming some value for t, plotting the expression doesn't seem to show a solution at w = t + t^2. I am sorry. I made a mistake. best Robert Dodier -- You received this message because you are subscribed to the Google Groups

Re: [sage-support] Re: solve(-(1/2*sqrt((4*w+1)+1))*t+w==0,w)

Thanks to Emmanuel Charpentier for the solution. But the trick is S1[0]^2 that needs human works. Le samedi 18 octobre 2014 11:58:37 UTC+2, Emmanuel Charpentier a écrit : Well, after a bit of sleep, the solution was (semi-)obvious : sage: var(w,t) (w, t) sage:

[sage-support] Re: solve(-(1/2*sqrt((4*w+1)+1))*t+w==0,w)

Hi! On 2015-03-09, platane guo...@gmail.com wrote: Thanks to Emmanuel Charpentier for the solution. But the trick is S1[0]^2 that needs human works. Sure. But that's a very common situation. Computers are very good in many computational aspects, but still human insight is needed to break a

[sage-support] Re: Solve Quadratic Programming in Sage

Hello guy, Your question looks like a modeling math problem, ...and is not related to SAGE. I wouln't try to solve quadratic problem using linear solvers : LP means Linear Programming for definition of LP, read http://www.sagemath.org/doc/reference/numerical/sage/numerical/mip.html more

[sage-support] Re: Solve MixedIntegerLinearProgram for variables that are limited to the given set

On 2014-12-11, pegah Ali pegah.aliza...@gmail.com wrote: --=_Part_141_146171712.1418307564716 Content-Type: multipart/alternative; boundary==_Part_142_2134155063.1418307564716 --=_Part_142_2134155063.1418307564716 Content-Type: text/plain; charset=UTF-8 Hello everybody,

[sage-support] Re: Solve MixedIntegerLinearProgram for variables that are limited to the given set

Hello Dima, Thank you for your response. It gave me some ideas :) On Thursday, December 11, 2014 3:19:24 PM UTC+1, pegah Ali wrote: Hello everybody, I am new to sage and try to solve the following LP with MixedIntegerLinearProgram: Maximization: 3.0 x_0 + 2.0 x_1 - 1.0

Re: [sage-support] Re: solve(-(1/2*sqrt((4*w+1)+1))*t+w==0,w)

Well, after a bit of sleep, the solution was (semi-)obvious : sage: var(w,t) (w, t) sage: E1=-(1/2*sqrt((4*w+1)+1))*t+w==0 sage: S1=E1.solve(w) sage: S1 [w == 1/2*t*sqrt(4*w + 2)] sage: S2=((S1[0])^2).solve(w) sage: S2 [w == 1/2*t^2 - 1/2*sqrt(t^2 + 2)*t, w == 1/2*t^2 + 1/2*sqrt(t^2 + 2)*t] A

[sage-support] Re: solve(-(1/2*sqrt((4*w+1)+1))*t+w==0,w)

Ahem ! On one machine : sage: sage.version.version '6.4.beta4' sage: var(w,t) (w, t) sage: solve(-(1/2*sqrt((4*w+1)+1))*t+w==0,w) [w == 1/2*t*sqrt(4*w + 2)] sage: maxima.version() '5.34.1' Another one : sage: sage.version.version '6.4.beta1' sage: var(w,t) (w, t) sage:

Re: [sage-support] Re: solve(-(1/2*sqrt((4*w+1)+1))*t+w==0,w)

2014-10-17 10:09 UTC, Emmanuel Charpentier emanuel.charpent...@gmail.com: Ahem ! On one machine : sage: sage.version.version '6.4.beta4' sage: var(w,t) (w, t) sage: solve(-(1/2*sqrt((4*w+1)+1))*t+w==0,w) [w == 1/2*t*sqrt(4*w + 2)] This solution is implicit. This is the problem. Vincent

Re: [sage-support] Re: solve(-(1/2*sqrt((4*w+1)+1))*t+w==0,w)

Le vendredi 17 octobre 2014 16:37:55 UTC+2, vdelecroix a écrit : 2014-10-17 10:09 UTC, Emmanuel Charpentier emanuel.c...@gmail.com javascript:: Ahem ! On one machine : sage: sage.version.version '6.4.beta4' sage: var(w,t) (w, t) sage:

[sage-support] Re: solve(-(1/2*sqrt((4*w+1)+1))*t+w==0,w)

On 2014-10-15, platane guo...@gmail.com wrote: solve does not solve ? sage: solve(-(1/2*sqrt((4*w+1)+1))*t+w==0,w) [w == 1/2*sqrt(4*w + 2)*t] Well, if I'm not mistaken, Sage punts to Maxima's 'solve' function, which, I'm sorry to report, is not very strong (it can solve a relatively narrow

[sage-support] Re: solve(-(1/2*sqrt((4*w+1)+1))*t+w==0,w)

sage: solve(-(1/2*sqrt((4*w+1)+1))*t+w==0,w) [w == 1/2*sqrt(4*w + 2)*t] Well, if I'm not mistaken, Sage punts to Maxima's 'solve' function, which, I'm sorry to report, is not very strong (it can solve a relatively narrow range of problems). But I find that Maxima's 'to_poly_solve'

[sage-support] Re: Solve for a function defined in a file?

Have zeros of order 2 too, so the sign change doesn't help in general, but may work for some zeros. Thank you!... On Saturday, June 21, 2014 1:21:06 AM UTC-7, Dima Pasechnik wrote: On 2014-06-21, David Ingerman davidd...@gmail.com javascript: wrote: Thank you, that's helpful. Is there a

[sage-support] Re: Solve for a function defined in a file?

On 2014-06-22, David Ingerman daviddavif...@gmail.com wrote: Thank you, that makes sense. My Python function is not continuous though, has poles, so I'll probably have to plot it to find its zeros... you might perhaps try finding a pole p by solving 1/f(x)=0, and regularise f by multiplying

[sage-support] Re: Solve for a function defined in a file?

Thank you, that's helpful. Is there a way to get all roots of a Python function on an interval? On Friday, June 20, 2014 2:10:38 AM UTC-7, Dima Pasechnik wrote: On 2014-06-20, David Ingerman davidd...@gmail.com javascript: wrote: Thank you, so what to do for Python function? Matlab had

[sage-support] Re: Solve for a function defined in a file?

On 2014-06-21, David Ingerman daviddavif...@gmail.com wrote: Thank you, that's helpful. Is there a way to get all roots of a Python function on an interval? I never heard of robust procedures for such a task, and doubt they are even possible (think about roots of sin(1/x) on [0,1]).

[sage-support] Re: Solve for a function defined in a file?

Thank you, that makes sense. My Python function is not continuous though, has poles, so I'll probably have to plot it to find its zeros... On Saturday, June 21, 2014 1:21:06 AM UTC-7, Dima Pasechnik wrote: On 2014-06-21, David Ingerman davidd...@gmail.com javascript: wrote: Thank you,

[sage-support] Re: Solve for a function defined in a file?

On 2014-06-20, David Ingerman daviddavif...@gmail.com wrote: Thank you, so what to do for Python function? Matlab had general purpose 'optim(f)' if my memory is right... you can e.g. use find_root(); this is a numerical thing that accepts Python functions. Here is an example: sage: def

[sage-support] Re: Solve for a function defined in a file?

Thank you, so what to do for Python function? Matlab had general purpose 'optim(f)' if my memory is right... On Wednesday, June 11, 2014 1:50:10 AM UTC-7, Dima Pasechnik wrote: On 2014-06-10, David Ingerman davidd...@gmail.com javascript: wrote: How to solve([f(x)==0],x) for a

[sage-support] Re: Solve for a function defined in a file?

On 2014-06-10, David Ingerman daviddavif...@gmail.com wrote: How to solve([f(x)==0],x) for a function f(x) defined in a .sage file? The error message: TypeError: Cannot evaluate symbolic expression to a numeric value. what is f(x) ? solve() won't work for a Python function, it needs a

Re: [sage-support] Re: solve() free variable substitution

Sorry to keep on here, but I've got three other related queries: (1) solve? gives me solve(sin(x)==x,x,explicit_solutions=True) as an example which returns an empty list of solutions. But x=0 surely counts as an explicit solution? I guess my interpretation of an empty list as

Re: [sage-support] Re: solve() free variable substitution

I've opened http://trac.sagemath.org/sage_trac/ticket/14738 for a lot of this stuff. It's all related to keywords not being sufficiently happy. There is a ticket for adding a lot of that to the main 'solve?' but Trac seems to be down right now so I can't find it...

[sage-support] Re: solve() free variable substitution

robin hankin wrote: hello, sage 5.9 If solve() gives an unspecificed integer, how do I substitute a particular value into the expression? subs() does not work as expected/desired because the free variables don't seem to be defined. sage: a=solve(sin(x)==0,x,to_poly_solve='force');a [x ==

[sage-support] Re: solve() free variable substitution

leif wrote: robin hankin wrote: hello, sage 5.9 If solve() gives an unspecificed integer, how do I substitute a particular value into the expression? subs() does not work as expected/desired because the free variables don't seem to be defined. sage:

[sage-support] Re: solve() free variable substitution

On Wednesday, June 12, 2013 8:09:02 PM UTC-4, leif wrote: robin hankin wrote: hello, sage 5.9 If solve() gives an unspecificed integer, how do I substitute a particular value into the expression? subs() does not work as expected/desired because the free variables don't

[sage-support] Re: solve() free variable substitution

kcrisman wrote: On Wednesday, June 12, 2013 8:09:02 PM UTC-4, leif wrote: robin hankin wrote: hello, sage 5.9 If solve() gives an unspecificed integer, how do I substitute a particular value into the expression? subs() does not work as expected/desired

Re: [sage-support] Re: solve() free variable substitution

On Thu, Jun 13, 2013 at 12:45 PM, kcrisman kcris...@gmail.com wrote: Smells like a bug... Not exactly. The documentation for solve makes it clear (I hope!) in the examples that these are generic variables generated by Maxima which we do not make Sage variables. They just mean, any old

[sage-support] Re: Solve system of non linear equations

I take it you mean polynomial equations: sage: AA.x,y = AffineSpace(GF(2),2) sage: S = AA.subscheme(x^2+y^2) sage: S.point_set().points() [(0, 0), (1, 1)] On Saturday, December 8, 2012 6:14:19 AM UTC, Santanu wrote: I have a system of non linear equations over GF(2). How to solve them in

Re: [sage-support] Re: Solve system of non linear equations

Or compute a Gröbner basis: sage: P.x,y = BooleanPolynomialRing() sage: Ideal(x^2 + y^2).groebner_basis() [x + y] sage: Ideal(x^2 + y^2).variety() [{y: 0, x: 0}, {y: 1, x: 1}] On Saturday 08 Dec 2012, Volker Braun wrote: I take it you mean polynomial equations: sage: AA.x,y =

Re: [sage-support] Re: Solve system of non linear equations

Thank you. But when I try to solve f1=x1 + x2 + x4 + x10 + x31 + x43 + x56 , f2=x2 + x3 + x5 + x11 + x32 +x44 + x57, it becomes very slow. Is there any faster approach like F4 algorithm available in Sage? On 8 December 2012 17:25, Martin Albrecht martinralbre...@googlemail.comwrote: Or

Re: [sage-support] Re: Solve system of non linear equations

On Saturday, December 8, 2012 11:07:31 AM UTC-6, Santanu wrote: Thank you. But when I try to solve f1=x1 + x2 + x4 + x10 + x31 + x43 + x56 , f2=x2 + x3 + x5 + x11 + x32 +x44 + x57, it becomes very slow. Is there any faster approach like F4 algorithm available in Sage? F4 is not yet

Re: Re: [sage-support] Re: Solve system of non linear equations

We are talking about the Boolean polynomial ring here, right? So an F4 style algorithm is used by default (subject to some heuristics). To emphasise you'd have to construct your ring using the BooleanPolynomialRing constructor. On Saturday 08 Dec 2012, john_perry_usm wrote: On Saturday,

[sage-support] Re: solve( ..., solution_dict=True) does not always return a list

On Jul 21, 9:03 pm, Marshall Hampton hampto...@gmail.com wrote: Ticket 8553 doesn't fix this, so while it is a related issue this will need a ticket of its own.  Looking at the source its not clear to me why your last example doesn't return a list. I

[sage-support] Re: solve() gives incorrect answers for nonlinear system?

Try something like this: from mpmath import * mp.dps = 30; mp.pretty = True f=[lambda s00, s01, s10, s11, k, p:0.55*k*s00 + 0.6*k*s01 + 0.6*k*s10 + 0.6*p*s01 + 0.6*p*s10 +0.55*p*s11 + 33*s00 + 33*s01 + 33*s10 + 33*s11 - 33.0, lambda s00, s01, s10, s11, k, p:0.55*k*s00 + 0.6*k*s01 + 0.6*k*s10 +

[sage-support] Re: solve( ..., solution_dict=True) does not always return a list

Ticket 8553 doesn't fix this, so while it is a related issue this will need a ticket of its own. Looking at the source its not clear to me why your last example doesn't return a list. I created http://trac.sagemath.org/sage_trac/ticket/11618 to address this. Hopefully someone from 8553 can fix

Re: [sage-support] Re: solve() gives incorrect answers for nonlinear system?

Thanks, this at least gives a reasonable answer and will work in the short-term. I'm still confused about why solve() didn't work, though. On Thu, Jul 21, 2011 at 11:44 PM, achrzesz achrz...@wp.pl wrote: Try something like this: from mpmath import * mp.dps = 30; mp.pretty = True

Re: [sage-support] Re: solve() exception when variable names contain brackets

On 06/29/11 16:28, Jason Grout wrote: On 6/29/11 3:22 PM, Michael Orlitzky wrote: This is probably just a case of don't do that, but I thought I'd check: sage: c = [ var('c[0]') ] sage: system = c[0]*x == 1 sage: solve(system, c[0]) boom ... TypeError: unable to make

[sage-support] Re: solve() exception when variable names contain brackets

On 6/29/11 3:22 PM, Michael Orlitzky wrote: This is probably just a case of don't do that, but I thought I'd check: sage: c = [ var('c[0]') ] sage: system = c[0]*x == 1 sage: solve(system, c[0]) boom ... TypeError: unable to make sense of Maxima expression '[c[0]==1/x]' in

[sage-support] Re: solve() exception when variable names contain brackets

Thats http://trac.sagemath.org/sage_trac/ticket/7496 and its scheduled for sage-4.7.2 -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at

[sage-support] Re: solve does not consider all a_x which are in the equation

Normally solve(e == m, a_x, to_poly_solve='force') works, but interestingly, not for your equation. Joal Heagney -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options,

[sage-support] Re: solve does not consider all a_x which are in the equation

Btw. I use sage 4.6.2. I wasn't aware that 4.7 allready exists. I will try out if the issue still exists in 4.7. -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit

[sage-support] Re: solve(eqts, solution_dict=True) gives IndexError if there's no solution for eqts

This is already mentioned here: http://www.mail-archive.com/sage-support@googlegroups.com/msg20832.html (It seems from that thread that this may not be a problem with Sage itself.) It should be reported as a bug if it hasn't been already. On May 17, 12:20 pm, tvn nguyenthanh...@gmail.com wrote:

[sage-support] Re: solve(eqts, solution_dict=True) gives IndexError if there's no solution for eqts

On May 18, 2:21 am, zsharon zacherysha...@gmail.com wrote: This is already mentioned here:http://www.mail-archive.com/sage-support@googlegroups.com/msg20832.html (It seems from that thread that this may not be a problem with Sage itself.) It should be reported as a bug if it hasn't been

[sage-support] Re: solve(eqts, solution_dict=True) gives IndexError if there's no solution for eqts

so is there someway we can do so that this patch or temporary solution be pushed into the next Sage release ? -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit

[sage-support] Re: solve(eqts, solution_dict=True) gives IndexError if there's no solution for eqts

On May 18, 9:17 am, tvn nguyenthanh...@gmail.com wrote: so is there someway we can do so that this patch or temporary solution be pushed into the next Sage release ?   Well, *you* can do that yourself - see, for instance,

[sage-support] Re: solve -- an easy issue with solution_dict=True)

Speaking about solve(), is there a place to report equations it cannot solve (and I believe it should?). I suppose putting it on the same Trac ticket is wrong practice? But should it be another ticket, or some yet other place? Robert Yup.  solve() probably needs a general overhaul (and has for

[sage-support] Re: solve -- an easy issue with solution_dict=True)

On Oct 19, 5:23 am, Robert Samal robert.sa...@gmail.com wrote: Speaking about solve(), is there a place to report equations it cannot solve (and I believe it should?). I suppose putting it on the same Trac ticket is wrong practice? But should it be another ticket, or some yet other place?

[sage-support] Re: solve -- an easy issue with solution_dict=True)

On Oct 12, 6:37 pm, Robert Samal robert.sa...@gmail.com wrote: I observed that solve behaves inconsistently in the following regards: sage: solve([x==1,x==-1],x) [] (this is as expected) However: solve([x==1,x==-1],x, solution_dict=True) produces an error message. Easy to live with,

[sage-support] Re: solve -- an easy issue with solution_dict=True)

On 13 okt, 03:39, kcrisman kcris...@gmail.com wrote: On Oct 12, 6:37 pm, Robert Samal robert.sa...@gmail.com wrote: I observed that solve behaves inconsistently in the following regards: sage: solve([x==1,x==-1],x) [] (this is as expected) However: solve([x==1,x==-1],x,

Re: [sage-support] Re: solve() problem

Hello everyone thanks for the help here. In Mathematica, Reduce[] works like Solve, except that it returns a Boolean list of possible solutions. I use it to check what the necessary conditions for thereal solution to work: MMA Reduce[a*x == b, {x}] MMA (b == 0 a == 0) || (a != 0 x ==

[sage-support] Re: solve() problem

Hi! On 19 Aug., 22:41, robin hankin hankin.ro...@gmail.com wrote: sagesolve([a*b==15*I-5,a*conjugate(b)==-13*I+9],[a,b]) [] So, from the first two lines I know that a=2+I, b=1+7I should be a solution to the system in the third, yet solve()  returns empty. Admittedly I am no expert for

Re: [sage-support] Re: solve() problem

Hello Simon thanks for this. One problem with the solution you mention is that I can't do the general case. What I need is the sage equivalent of mathematica's Reduce[] function. Is there one? rksh On Thu, Aug 19, 2010 at 10:06 PM, Simon King simon.k...@nuigalway.ie wrote: Hi! On 19

[sage-support] Re: solve() problem

On Aug 19, 5:39 pm, robin hankin hankin.ro...@gmail.com wrote: Hello Simon thanks for this. One problem with the solution you mention is that I can't do the general case.  What I need is the sage equivalent of mathematica's Reduce[] function. I think that solve() is the closest that

[sage-support] Re: solve polynomial limit?

Gak! I found it a work around: find_root() seems fine. Sorry for the interruption! On Apr 16, 10:47 am, Owen o...@backspaces.net wrote: I'm solving recurrence relations for a k-SAT algorithm, and have run up against an apparent limit in solve.  I'm running: solutions = solve([x^3 - x^2 - x -

Re: [sage-support] Re: solve polynomial limit?

On Fri, Apr 16, 2010 at 9:57 AM, Owen o...@backspaces.net wrote: Is there another method approach I could take?  I'd like to reach 6 at least.  My homework depends on it!  :) There's also the to_poly_solve argument to solve which cause non-exact answers to be returned: sage: solve([x^5 - x^4 -

Re: [sage-support] Re: solve issue

You can also use find_root: sage: h1 = var('h1') sage: eq = (6000*(h1/2)/(((1/12)*0.1125*(h1^3)) - ((1/12)*(0.1125-0.012)*((h1-(2*0.012))^3 == 8928880.28799800 sage: eq.find_root(-1.2, -0.8) -0.96594148395195312 sage: eq.find_root(-0.8, 0.2) 0.00033054212748907948 sage: eq.find_root(.2, 1)

[sage-support] Re: solve issue

The problem related to conversion of h1into maxima has been reported at http://trac.sagemath.org/sage_trac/ticket/8634 Robert -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more

[sage-support] Re: solve issue

Try to_poly_solve=True sage: h1=var('h1') sage: solve ([(6000*(h1/2)/(((1/12)*0.1125*(h1^3)) - ((1/12)*(0.1125-0.012)*((h1-(2*0.012))^3 == 8928880.28799800], h1,to_poly_solve=True) [x^k*binomial(n, k) == -0.965941485371, x^k*binomial(n, k) == 0.000330542127524, x^k*binomial(n, k) ==

[sage-support] Re: Solve fails for a cubic

On Mar 1, 3:02 am, Alex Ghitza aghi...@gmail.com wrote: On Sun, 28 Feb 2010 23:02:08 -0800 (PST), Sharpie ch...@sharpsteen.net wrote: However, tonight I have been trying to solve an open channel flow problem which requires me to find the roots of:   y^3 - 1.39027132807289 * y^2 +

Re: [sage-support] Re: Solve fails for a cubic

On Tue, 2 Mar 2010 05:27:45 -0800 (PST), Sharpie ch...@sharpsteen.net wrote: Thanks for the reply Alex. I think I understand that by choosing a variable of the appropriate type, in this case one that is restricted to the real numbers, the roots can be determined in a straight-forward manner.

[sage-support] Re: Solve fails for a cubic

On Mar 2, 2:34 pm, Alex Ghitza aghi...@gmail.com wrote: The way I see it, it is not actually a question about the variable representing a real number; it is more a question of using polynomials and their specialised built-in roots() method rather than symbolic functions and the general-purpose

[sage-support] Re: Solve fails for a cubic

On Mar 2, 8:10 pm, Sharpie ch...@sharpsteen.net wrote: So I guess at this point my question is: is there another way to convert from a symbolic polynomial equation to a Polynomial Ring?  I The methods I used feel very hacky and I don't trust them. Ok, so I think I found something in the manual

[sage-support] Re: Solve recurrences using Sage ?

Should we create a ticket for this ? I'd have done it if not for my doubt on the section I should pick for this... :-) Nathann On Feb 10, 1:42 pm, Harald Schilly harald.schi...@gmail.com wrote: On Feb 10, 11:16 am, Simon King simon.k...@nuigalway.ie wrote: sage: f = y(n+2) - y(n+1) - y(n)

[sage-support] Re: Solve recurrences using Sage ?

On Feb 10, 9:54 am, Nathann Cohen nathann.co...@gmail.com wrote: I just learnt about the rsolve function from Maple, which seems to give the formula of sequences defined by recurrence.. Is there a similar function in Sage ? sympy has rsolve For example, how could I have Sage give me the

Re: [sage-support] Re: Solve recurrences using Sage ?

sage: f = y(n+2) - y(n+1) - y(n) sage: rsolve(f, y(n), { y(0):1, y(1):1 }) (1/2 + 5**(1/2)/2)**n/2 + (1/2 - 5**(1/2)/2)**n/2 - 5**(1/2)*(1/2 - 5**(1/2)/2)**n/10 + 5**(1/2)*(1/2 + 5**(1/2)/2)**n/10 That's perfect !! Thank you very much !! :-) Their interface is a bit clumsy though, I admit... It

[sage-support] Re: Solve recurrences using Sage ?

On Feb 10, 9:55 am, Harald Schilly harald.schi...@gmail.com wrote: For example, how could I have Sage give me the general formula of fibonacci's sequence ? :-) I wasn't able to do that one Perhaps like that: sage: from sympy import * sage: y = Function('y') sage: n =

[sage-support] Re: Solve recurrences using Sage ?

Hi Nathann! Your were faster than I ... :-) On Feb 10, 10:13 am, Nathann Cohen nathann.co...@gmail.com wrote: Their interface is a bit clumsy though, I admit... It could be good to be able to do it directly in Sage :-) But how would a better interface look like? I mean, you define a

Re: [sage-support] Re: Solve recurrences using Sage ?

Well, for example : - You need to import simpy to use it - For this reason, it does not appear in Sage's documentation - It could be good to be able to define functions and variables as they usually are in Sage and not through Simpy types - Only define one function... I'd have enjoyed the ability

Re: [sage-support] Re: Solve recurrences using Sage ?

Hi Nathann, On Wed, Feb 10, 2010 at 9:25 PM, Nathann Cohen nathann.co...@gmail.com wrote: Well, for example : - You need to import simpy to use it One either directly import the functionalities of a third-party package, or have them imported automatically at Sage startup. But consider for a

[sage-support] Re: Solve recurrences using Sage ?

On Feb 10, 11:16 am, Simon King simon.k...@nuigalway.ie wrote: sage: f = y(n+2) - y(n+1) - y(n) ahh ... ok. now i get it ^^ When I look into sympy/solvers/recurr.py right the first thing rsolve does is to compute lhs - rhs. So, f = y(n) == y(n-1) - y(n-2) *should* work. But it doesn't, because

Re: [sage-support] Re: Solve recurrences using Sage ?

I mentionned having to import simpy.*, which included classes like Symbol or Function, and having to use those types. I wouldn't personally mind if I had to import rsolve from some Sage class... Why should it necessarily imported by default (namespace kept clean)? Nathann -- To post to this

[sage-support] Re: Solve recurrences using Sage ?

Regarding namespace pollution. Mathematica has thousands of function names in it's global namespace but it never causes programmers a problem because they have a convention. All mathematica functions start with a capital: Integrate, Plot, ListPlot etc. So, stick to lower case variables and you

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