Hello everybody,

I develop a simulator of dynamical systems governed by ODE systems.
Thanks to intensive upstream testing I have already identified some "methods" that work well on some classes of systems and poorly for some others (here "method" is intented in the sense of dsolve(..., numeric, method=...)), but it is rather difficult to know in advance if method A will perform well or not, or if method B could be better ...
This is very classical.

On the other side, people this simulator is designed for, do not want to use directly MAPLE to  choose a method among all those it proposes,nor to adjust the many parameters some methods can have

The idea I have in mind is to facilitate their choice by developing a specific Maplet. This Maplet could take as a model the pane dsolve[interactive]() opens when you select the numerical solving strategy.
As far as possible I would like to customize this pane for it be closer to our own needs (specific options sholud be proposed as well as personal help pages)

So my questions:

1/  Is the corresponding code avaliable (I failed to find it while using showstat) ?
1'/ Incidentally, even if this simulator is designed for internal purposes alone, is there some kind of copyright or usage limitations of the code above ?
2/ Is it possible to obtain the list of all the avaliable methods (euler, rk4, gear, ...) without without constructing it manually ?
3/ Once a method is choosen, is it possible to obtain the list of all its options (here again without without constructing it manually) ?

Maybe a quite unusual request on this site but I would greatly appreciate any answer

Thanks in advance

Hi,

I want to solve 2 linear equations in p[1] and p[2] 

eq3 = -(1/8)*(x^2+y^2+((x^2+y^2)^2+2*(omega[1]-omega[2])*(x^2-y^2)+(omega[1]-omega[2])^2)^(1/2)+omega[1]-omega[2])*(x^2*p[1]+2*x*y*p[2]-y^2*p[1]-((x^2+y^2)^2+2*(omega[1]-omega[2])*(x^2-y^2)+(omega[1]-omega[2])^2)^(1/2)*p[1]+omega[1]*p[1]-omega[2]*p[1])/(y^2*x*(omega[1]-omega[2])) - P[1];
eq4 = -(1/8)*(x^2*p[1]+2*x*y*p[2]-y^2*p[1]+((x^2+y^2)^2+2*(omega[1]-omega[2])*(x^2-y^2)+(omega[1]-omega[2])^2)^(1/2)*p[1]+omega[1]*p[1]-omega[2]*p[1])*(x^2+y^2-((x^2+y^2)^2+2*(omega[1]-omega[2])*(x^2-y^2)+(omega[1]-omega[2])^2)^(1/2)+omega[1]-omega[2])/(y^2*(omega[1]-omega[2])*x) - P[2]

solve({eq3,eq4},{p[1],p[2]});

I don't receive any answer. Why?

plz code and sole that this integral!!!!!!!!!!

!!!

Hello people in mapleprimes,

I hope that you will give me an answer about the calculation surrounding D.
D((x+y)^2) can be calculated with maple, but D((x+y)^a), where a is a constant, cannot at least directly.
And, I have the code, which Mr. Carl Love kindly gave me at
http://www.mapleprimes.com/questions/218045-Logarithmic-Derivative
, which is

h:= F-> expand(evalindets(D(F)/F, specfunc(D), d-> op(d)*'h'(op(d))));

This works for (x+y)^2, but does not work for (x+y)^a.
And, I think this reason is that the behavior of D to (x+y)^2 is not the same
 as that to (x+y)^a.
And, I want to modify this code.
But, I can't .
So, I am asking this question. How should I modify the above code so that it works for (x+y)^a.
I'm so sorry for a lot of impoliteness.
I will be very glad if you give me an answer.

Take care.

taro

I have 

dZ(x)=−xdlog(z(x))

where d is the exterior derivative. I would like to recover the function Z(x) by integrating both sides of the equation. How would I compute this in Maple?

I recently got a laptop with an HD display (2560x1440).

While I can make the maple intput (and 2D math output) big enoght via zooming (ctrl+<number>), the default plots are unusable (everything is too small). This is true for "widges" created with Explore as well.

Has anyone come across this? If so how do you deal wit this problem? 

It would be nice if Maple could scale it's interface and default sizes of various elements properly for HD displays.

I am working on a maple lab assignment and we dont actually learn maple for the class we just use it do 5 assignment the whole semster. This one consists of damping and differential equations which we have not learned. I was wondering if anyone knew how to carry it out. Well here is the part where I have an issue: 

Our solutions in the critically damped and overdamped cases approach the θ = 0 axis without crossing it, but if the initial velocity is directed toward the equilibrium position and is sufficiently large the pendulum will “overshoot”, passing the equilibrium position before settling back toward it. Experiment with this effect with a new value µ = 8 of the damping constant to give overdamped motion: introduce a new initial condition (give it a new name), keeping θ(0) = 1 but changing θ '(0) until you find a value which produces an overshoot of about 0.1 radian. Include in the worksheet only the graph showing this overshoot and the commands needed to produce that graph. In the discussion section give explicitly the value of the initial velocity that you found.

And this was the original initial condition and equation code:

K:=9; deG:=diff(theta(t),t,t) + mu*diff(theta(t),t)+K*sin(theta(t))= 0; deL:=diff(theta(t),t,t) + mu*diff(theta(t),t)+K*theta(t)= 0; Iv:=theta(0)=1, D(theta)(0)=5; dom1:=t=0..10;

I am not too sure how to manipulte this to work. Any help is welcome. 

hi there,

this is my first post here, and first time using maple

I do have trigonometric system of equations, and I like to solve for thetas(1-5).

please help me out( how do I inpu them in maple) and how to solve them? 

Hi.

I have 2 expressions, the first expression cosist of x´s and y´s, the other expression consits only of x´s

I wanna test the relation between those 2 expression to check wether A>B giving the condition that 2y<x

I have tried this:

assume(2y<x);

is(A>B);

the problem is that maple returns FAIL, I could put in values to check and it works, but that is not really what im trying to acomplish.

Thanks

Please help me to solve the system of 1st order singular O.D.E  (see uploaded file)....New_Microsoft_Office_Word_Document.docx
 

Hi Maple Primes,

Can this code be improved?

I know that the Goldbach Conjecture has been checked with computer tools above 10^10.

Request for comments.

check_g_conjecture_26_b.mw

check_g_conjecture_26_b.pdf

Regards

Matt

Hello,

I am working on a Dirichlet breakdown of primes. I need a way to check if a number is part of anothers number factorization.

Example: 30 = 2*3*5.

2 is therefore part of the ifactor of 30. 4 and 7 are not.
How do I check if, for instance, 7 is part of de factorization of 390?

Thanks in advance.

Hello,

I tried to define the Poisson bracket in this way

restart:
Ps:=proc(f,g)
local P;
P:=simplify(diff(f,P[1])*diff(g,X)-diff(f,X)*diff(g,P[1])+
diff(f,P[2])*diff(g,Y)-diff(f,Y)*diff(g,P[2]));
end;

The problem is that, if I ask Ps(P[1],X) I got 0 which is clearly wrong.

Where is the error?

https://dl.dropboxusercontent.com/u/51122291/Scrreshot.jpeg

Thanks Nicola 

Just a simple graphical view of Maple releases over the years.

with(plots):
MapleVersions := [[1, 1982], [1.1, 1982.05], [2, 1982.33], [2.1, 1982.42], [2.15, 1982.58], [2.2, 1982.92], [3, 1983.17], [3.1, 1983.75], [3.2, 1984.25], [3.3, 1985.17], [4, 1986.25], [4.1, 1987.33], [4.2, 1987.92], [4.3, 1989.17], [5.1, 1990.58], [5.2, 1992.83], [5.3, 1994.17], [5.4, 1996], [5.5, 1997.83], [6, 1999.92], [7, 2001.5], [8, 2002.25], [9, 2003.42], [9.5, 2004.25], [10, 2005.33], [10.01, 2005.58], [10.02, 2005.83], [10.03, 2006.17], [10.04, 2006.42], [10.05, 2006.5], [10.06, 2006.75], [11, 2007.08], [11.01, 2007.5], [11.02, 2007.83], [12, 2008.33], [12.01, 2008.75], [12.02, 2008.92], [13, 2009.25], [13.01, 2009.5], [13.02, 2009.75], [14, 2010.25], [14.01, 2010.75], [15, 2011.25], [15.01, 2011.42], [16, 2012.17], [16.01, 2012.33], [17, 2013.17], [17.01, 2013.5], [18, 2014.17], [18.01, 2014.33], [18.015, 2014.5], [18.02, 2014.83], [19, 2015.17], [19.1, 2015.33], [20, 2016.17], [20.1, 2016.25], [20.15, 2016.30]]
a:=map(ListTools:-Reverse,MapleVersions): #swap x-y axis
plot(a, style = point, symbol = point)