Unanswered Questions

This page lists MaplePrimes questions that have not yet received an answer

I find mapleform software   but I dont know how to use , and does anyone know another method to convert.  I know use 

> with(MmaTranslator);
> MmaToMaple();  

I can  automatically translated .nb files.  but this have  

Error, (in readline) file or directory does not exist
Error, (in readline) file or directory does not exist
Error, (in readline) file or directory does not exist
Error, (in readline) file or directory does not exist

another Error, missing operator or `;`

also I try to use 

> with(MmaTranslator);
> FromMmaNotebook(Mma_notebook_filename, options);

I still dont know how is works?  can you explains for me and show me some example  , here is my example files.plot.zip

 

Hello,

I need to model some spherical joints with damping.

Apparently, contrary to revolute joints, it seems that it is not possible to add damping in spherical joints. Indeed, contrary to the revolute joint where there is an option to put spring or damping element, i don't find this option in the spherical joint. 

Do you have a idea to model spherical joints with damping (without changing the spherical joint)?

Thanks a lot for your help

During a lengthy computation of mine - done using a well established and scientifically sensible external package - I get a Too many level of recursion error in PDEtools/NumerDenom.

Since it has always worked fine for simpler computation with the exact same code, I am wondering whether, with a bigger bound of the level of recursion, the computation could be succesful.

Which is the max level of recursion than maple allows?

Is it possibile to manually (at one's own risk) raise it, in the same line as raising, for instance, stacklimits kernel option?

Hello,

 

I want to simulating a mulitibody system, similar circular motion.

schematic diagram:

 

result:

 

Why the ball cannot keep on the circle?

 why_split.msim

Thanks

When I print a Table with graphs in it, the graphs are compressed vertically to an extreme extent. There has to be some compression from the screen, of course, since I have a wide-screen (although the actual worksheet does not use the whole screen width because of the palette and the fact that I don't use full-screen mode. However, the vertical compression  (that is, in a direction where there is plenty of room on the page) is many times more than the horizontal compression. In order to get the printed graph to look normal, I have to stretch the screen graph vertically an extreme amount, which, of course, looks horribly distorted on the screen.

Also when printing a graph as part of a Table, the graph area is clipped so that the title and legend do not print.

I thought that the Table struction would be a good way to display related graphs. But this behavior is making the use of Tables tedious and much less satisfactory because of the missing titles and legends.

None of these things happen when I print a graph in a regular execution group outside a Table structure.

Has anybody else had this problem, and have you found a way to avoid the compression and get the legends?

I have been trying to fit a function to experimental data. To do this i was using

.

The data is of the type

.

When I use initialvalues, I get a result, that fits the data well, but is clearly not the desired minimum. Maple delivers g always bigger than 10000 which is nowhere near -7, where it has to be for physical reasons. When using parameterranges I get the error

Warning, no iterations performed as initial point satisfies first-order conditions.

He stopps computing and simply prints out my initialvalues or the first value that is in the parameterrange with a huge RSS.

How can I use initialvalues and parameterranges together for my data?

Hey

As a lot of people before me I'm severely dissappointed my Maple's ability to export a .mw file to .tex.

The output looks horrible and even disappears off the side of the page in some places.

I've searched far and wide on the internet but it's difficult for me to understand the few, outdated, results I've dug up.

 

Is it completely impossible to get my hands on a good (or just working) Maple 18 to LaTex exporter? It's not possible for me to begin coding my own.

Hi all, I am new to MAPLE, I have been using Mathematica mostly. Here is what i am trying to do in MAPLE, 

Use the procedure plotmotion 2 on the plotmo worksheet to animate the motion of a marble in a bowl of the shape of the bottom half of the ellipsoid x^2/16 + y^2/12 +z^2/9 = 1

Can anyone help? It will be greatly appreciated.

Hi Maple People,

I got stuck trying to write a procedue for my project today.  My topic is Prime Constellations.

If you want to help me, please read my primer on constellations

https://docs.google.com/viewer?a=v&pid=sites&srcid=ZGVmYXVsdGRvbWFpbnxwcmltZWNvbnN0ZWxsYXRpb25zfGd4OjNmOWZlNWQxZDY2ODY4YmQ

The procedure should refine an offset Vector and increase a multiplier scalar.

 

I want to delay putting the broken procedure until I can simplify it and try again.

Thanks,

Matt Anderson

hi friends

I encountered a problem and I can not draw the plot of this code

> sol := fsolve({diff(S, x) = 0, diff(S, y) = 0}, {x, y});



> with(VectorCalculus);
> with(linalg);
> s1 := evalf(subs(sol, linalg[grad](S, [x, y])));

> with(VectorCalculus);
> with(LinearAlgebra);
> s2 := evalf(subs(sol, linalg[hessian](S, [x, y]))); pmp0 := [x-subs(sol, x), y-subs(sol, y)]; sapprox := s0+evalm(`&*`(`&*`(transpose(pmp0), s2), pmp0));
> with(Statistics);
>
> with(stats); statevalf[icdf, chisquare[4]](.95);

> with(VectorCalculus);
> with(plottools);
> with(plots);
> with(linalg); ellips := {seq(stats*([statevalf[icdf, chisquare[4]]])(c) = sapprox, c = [.5, .95, .999])};
> plots(ellips(x, y), x = 950 .. 1000, y = 700 .. 750, grid = [50, 50], view = [950 .. 1000, 700 .. 750]);

 

 

can you helpe me?Thank you

Dear Friends,

I am solving 6 ODEs using maple15. then i got this error. anyone know abou this? thank you.

problem2.mw

 

 

restart:with (plots): B:=1:M:=1:Gr:=0.5:Pr:=3:w:=0.02:blt:=5:Bi:=10:

Eq1:=diff(f(eta),eta,eta,eta)-(diff(f(eta),eta))^(2)+f(eta)*diff(f(eta),eta,eta)+B*H(eta)*(F(eta)-diff(f(eta),eta))-M*diff(f(eta),eta)+Gr*theta(eta)=0;

diff(diff(diff(f(eta), eta), eta), eta)-(diff(f(eta), eta))^2+f(eta)*(diff(diff(f(eta), eta), eta))+H(eta)*(F(eta)-(diff(f(eta), eta)))-(diff(f(eta), eta))+.5*theta(eta) = 0

(1)

Eq2:=(1+Nr)*diff(theta(eta),eta,eta)+Pr*f(eta)*diff(theta(eta),eta)+(2/3)*H(eta)*B*(theta1(eta)-theta(eta))=0;

(1+Nr)*(diff(diff(theta(eta), eta), eta))+3*f(eta)*(diff(theta(eta), eta))+(2/3)*H(eta)*(theta1(eta)-theta(eta)) = 0

(2)

Eq3:=H(eta)*F(eta)+H(eta)*diff(G(eta),eta)+G(eta)*diff(H(eta),eta)=0;

H(eta)*F(eta)+H(eta)*(diff(G(eta), eta))+G(eta)*(diff(H(eta), eta)) = 0

(3)

Eq4:=F(eta)^2+G(eta)*diff(F(eta),eta)+B*(F(eta)-diff(f(eta),eta))=0;

F(eta)^2+G(eta)*(diff(F(eta), eta))+F(eta)-(diff(f(eta), eta)) = 0

(4)

Eq5:=G(eta)*diff(G(eta),eta)+B*(f(eta)+G(eta))=0;

G(eta)*(diff(G(eta), eta))+f(eta)+G(eta) = 0

(5)

Eq6:=G(eta)*diff(theta1(eta),eta)+l*B*(theta1(eta)-theta(eta))=0;

G(eta)*(diff(theta1(eta), eta))+l*(theta1(eta)-theta(eta)) = 0

(6)

bcs:=f(0)=0,(D(f))(0)=1,(D(theta))(0)=-Bi*(1-theta(0)),(D(f))(blt)=0,F(blt)=0,G(blt)=-f(blt),H(eta)=w,theta(blt)=0,theta1(blt)=0;

f(0) = 0, (D(f))(0) = 1, (D(theta))(0) = -10+10*theta(0), (D(f))(5) = 0, F(5) = 0, G(5) = -f(5), H(eta) = 0.2e-1, theta(5) = 0, theta1(5) = 0

(7)

L:=[0.5,1,1.5,2];

[.5, 1, 1.5, 2]

(8)

for k from 1 to 4 do p:=dsolve(eval({Eq1,Eq2,Eq3,Eq4,Eq5,Eq6,bcs},Nr=L[k]),[f(eta),F(eta),G(eta),H(eta),theta(eta),theta1(eta)],numeric,output=listprocedure);end do:

Error, (in dsolve/numeric/bvp) unevaluated names in system not allowed: {Y[9], Y[10]}

 

``

``

``

 

Download problem2.mw

I have generated a picture using pointplot and display that creates a grid of colors based on the angle between vectors and (1,0) in R^2. Each angle is given a unique color via the HSV color space. I would like to provide a legend explaining the colour, something along the lines of

red (brown) green (blue) red
0                Pi                 2*Pi

and possibly

red       (brown)       green 
angle1                     angle2   

Is there an easy way to do this, or will I have to mess around with a custom pointplot/textplot solution?

Is it possible to use an option similar to range when using lsode method for dsolve? The ODEs I am trying to solve is stiff and will not work with the flag stiff=true or with method=rosenbrock unless i set Digits:=20. I want to avoid doing that as much as possible, since I believe wit will be very taxing, computationally. I have a very large systeom to solve. I found that method=lsode works with the default Digits=15. 

 

However I need to have the solutions in a given range stored for future access and manipulations. Using range gives me an error: 

Error, (in dsolve/numeric/an_args/lsode) lsode keyword was range, optional keyword must be one of 'ctrl', 'initial', 'itask', 'output', 'procedure', 'procvars', 'start', 'number', 'abserr', 'relerr', 'maxfun', 'minstep', 'maxstep', 'initstep', 'startinit', 'implicit', 'optimize', 'complex'

 

I cannot figure out how to use range or something similar with lsode. Anyone knows? 

Hi! I have to solve a very large system of ODEs for a set of functions that can be indexed with two integers, n and l, call them f[n,l](x), where n ranges from 1 to an order 1000 number and l ranges from 1 to an order 10 number. 

What is the best strategy in dsolve, keeping in mind I will only need to have quick access to the values of the first few such functions, say f[0,0](x) and f[0,1](x) for any given x in a given range. I dont need to store the rest, and trying to store all of them actually will give me a warning about length of output exceeds limit of 1000000. So, having maple output the result of dsolve in a procedural form seems to be what I want. However in doing so, for evey value of x i call the solving procedure maple will solve the system each time, thus taking a long time. 

 

My dilema is: to save storage space and memory I want to use dsolve output as procedures. To save time, when accessing the functions I need (only the first few in the large set of unknown functions that obey the ODE) for a given value of x, I would like maple to have those already stored instead of computing them with each invocation. So, what I need is a somehow split behavior of output. For some of my unknown functions to act as if i use range in dsolve, so that I have access at the values without further computation, and for the rest of the solutions (most of the unknown functions) just keep them in procedural form. How do I achieve this? 

 

Below is a schematic of my probem:

 

ODEs:={Set of about 10000 coupled ODEs for functions labeled f[n,l] n ranging from 1..1000 and l from 1..10}

 

dsolve(ODEs,numeric, output=???)#What options to put in dsolve such that I have quick access to f[0,0](x) and f[0,1](x) in a given range (say xmin=0.1 and xmax=10 for example) but not store the rest. 

 

 

Hi, 

     I have a question regarding pdsolve, or Solve from the PDEtools package. I have a set of equations relating partial derivatives, and I'd like to isolate certain terms without explicitly known the functions. I can do this for a single equation, but not multiple ones. I'm curious if Maple can currently handle a system of eqns like these easily, since I will be increasing the number of eqns in the future. Here's the code 

 

 

restart;

PDEtools:-declare(H=H(x,y,t)):

H(x, y, t)*`will now be displayed as`*H

(1)

eq1:= H[tt](x,y,t) = H[xx](x,y,t) + H[yy](x,y,t);

H[tt](x, y, t) = H[xx](x, y, t)+H[yy](x, y, t)

(2)

eq2 := diff(H[tt](x,y,t), t) = diff(H[tx](x,y,t), x) + diff(H[ty](x,y,t), y);

diff(H[tt](x, y, t), t) = diff(H[tx](x, y, t), x)+diff(H[ty](x, y, t), y)

(3)

eq3 := diff(H[tx](x,y,t), t) = diff(H[xx](x,y,t), x) + diff(H[xy](x,y,t), y);

diff(H[tx](x, y, t), t) = diff(H[xx](x, y, t), x)+diff(H[xy](x, y, t), y)

(4)

eq4 :=diff(H[ty](x,y,t), t) = diff(H[xy](x,y,t), x) + diff(H[yy](x,y,t), y);

diff(H[ty](x, y, t), t) = diff(H[xy](x, y, t), x)+diff(H[yy](x, y, t), y)

(5)

PDEtools:-Solve(eq3, H[xy]);

H[xy](x, y, t) = Int(diff(H[tx](x, y, t), t)-(diff(H[xx](x, y, t), x)), y)+_F1(x, t)

(6)

PDEtools:-Solve({eq1, eq2, eq3, eq4}, H[xy]);

Error, (in pdsolve/sys) the input system cannot contain equations in the arbitrary parameters alone; found equation depending only on {H[tt](x,y,t), H[xx](x,y,t), H[yy](x,y,t)}: H[tt](x,y,t)-H[xx](x,y,t)-H[yy](x,y,t)

 

 

 

 

Download PDESolveHelp.mw

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