Hi! I am trying to plot and store in memory some specific combinations of the solutions of the systems of ODEs that I get numerically from dsolve for a particular range of the independent variable. 

A particular case for my problem is the following system of stiff ODEs for two unknown functions f[0,0](x) and f[1,0](x) beween xini (where the Initial conditions are defined) and xfin, an arbitrary value of x. Note that rosebrock method does not work, and I can only solve it with lsode[adamsfull] or lsode[backfull]. I am attaching a maple file that shows what I have done.

Download Test2ODEs.mw

The approach in that file works, however I have a question regarding the efficiency of my method, since I plan to extend the system to many more ODEs besides just 2 and also extend the range to a larger xfin. In this method, since I define the function to plot in terms of f01 and f02, wich are procedures, does this mean that for each x on the grid for the plot(ftoplot,x=xini..xfin) maple actually computes the solutions f00(x) and f01(x) and then forms the ftoplot combination and plots that specific point? If the default sampling of my interval is, say 1000 points, does it mean that the way I wrote it I will have 1000 invocations of the dsolve procedure, for each x in the sample? I am not sure, it seems to me that is the case. This would imply that instead of advancing the solution at each step maple starts over again from xini. How could I just avoid this behavior and instead have access to the values of ftoplot(x) in the range xini to xfin stored from one invocation of dsolve? 

The ideal scenario for me would be to have f[0,0](x) and f[0,1](x) stored as an interpolated function between xini and xfin from the solutions of one invocation of dsolve prior to defining ftoplot. Can this be achieved in principle? How? Remember, i have to use method=lsode and range is not accepted.  

hi friends

After this cods i see very error

 > restart;

read(orbit.sav ): whit(plots):
ax := -G*Mz*x/(x^2+y^2)^(3/2);
ay := -G*Mz*y/(x^2+y^2)^(3/2);
i := 'i'; j := i+1;
for k from 0 to 3 do
x := 7*10^6; Vx := 0;
y := 0; Vy := 9000;
dt := evalf(1/2^k);
for i from 0 to 328 do
X[i] := evalf(x); Y[i] := evalf(y);
for n to 40*2^k do
x := evalf((1/2)*ax*dt^2+Vx*dt+x); y := evalf((1/2)*ay*dt^2+Vy*dt+y);
Vx := evalf(ax*dt+Vx); Vy := evalf(ay*dt+Vy)
od;
if i mod 41= 0 then
dX[k, i] := X[i]-XS[j]; dY[k, i] := Y[i]-YS[j]
fi
od;
p[k] := plot([seq([(X[i]-XS[j])*(1/1000), (Y[i]-YS[j])*(1/1000)], i = 0 .. 328)], color = green) end do;
p1 := display({seq(p[k], k = 0 .. 3)}, thickness = 3)
SI := [seq(41*i, i = 0 .. 8)]
p2 := plot({seq([seq([(1/1000)*dX[k, i], (1/1000)*dY[k, i]], k = 0 .. 1), [0, 0]], i = SI)}, color = black)
display({p1, p2}, scaling = constrained, labels = ['dx', 'dy'])
display({p1, p2}, view = [-.1 .. .5, -.4 .. .2], scaling = constrained, labels = ['dx', 'dy'])

can you help me Please?

Thank you

Does anyone know how to using some softward convert ?  for example  I have maple code , but I want to using mathematica code .I need fast way.

To run Maple script, on windows, I type

cmaple.exe   my_file.mpl

and this works well. So if my_file.mpl has the line int(sin(x),x);  the result of the above is:

> int(sin(x),x);
                                                        -cos(x)
> quit
memory used=0.9MB, alloc=8.3MB, time=0.05

sometimes, it will be nice to use cmaple to quickly do one time calculation on the fly such as the above, without having to open Maple GUI or write/edit a file. For example, I'd like to be able to do something like

cmaple.exe   "int(sin(x),x);"

but ofcourse the above does not work as is, since it expects its input to be a file. I tried

cmaple.exe   << "int(sin(x),x);"

but that did not work (for obvious reasons, since the input string is not a file name).

I tried different re-directions, as shown in this page for windows, but maple expects the input to be a file.

Is there a way to use cmaple with command directly written as string as above? I am using Maple 2015.

There is no menu item called "Startup Code"

in the "Edit" menu item of my Maple 13.

Please help!

Thanks!

We're starting on indefinite integrals in my 1st year calculus class.

A quick example would be int(sin(x), x);=-cos(x)+C

Maple doesn't add the +C on the end of it's solution. Can someone explain or point me to a resource? I've tried searching but I can't find an answer. 

Dear,

I have a perfectly working when all parameters are known (figure 1), however I want to perform a sensitivity analysis by derivating the code if one parameter is unknown. Because of multiple possible answers and because of the complexity of the formula, I cannot run this script and get solutions. Any ideas how I can this calculation lighter so it is able to run? Values should be real and positive (so 1 or 2 solutions are the only one I'm interested in)

Any ideas, how I can make this code runnable? (file is below)

I'm stuck on this for a while now :/ So I hope someone will be able to help me

Many thanks in advance!l

Question.mw

Figure 1: [URL=http://s1240.photobucket.com/user/laggstar/media/Parameter%20f%20known.png.html][IMG]http://i1240.photobucket.com/albums/gg494/laggstar/Parameter%20f%20known.png[/IMG][/URL]

Figure 2: [URL=http://s1240.photobucket.com/user/laggstar/media/Parameter%20f%20unknown.png.html][IMG]http://i1240.photobucket.com/albums/gg494/laggstar/Parameter%20f%20unknown.png[/IMG][/URL]

This should be trivial but I am not able to figure out the right syntax to execute it

The pdf is given by :

f_X(x)={ 1/25 *x, 0<=x<5

             2/5 -x/25, 5<=x<10

             0, otherwise

I have tried to use the "CumulativeDistributiveFunction" so far

Hi!

I am trying to solve a large nxl system of coupled differential equations. Maple seems to have trouble even for small n's so I wanted to know if anyone has any suggestions. Take the case of the following system of ODEs for my unknown functions f[0,0](x) and f[1,0](x). 

ODEs:= {diff(f[0, 0](x), x)+2.*f[0, 0](x)/x^5+.5000000000*f[0, 0](x)/x = -15.58845727*sin(.5773502693*x)/x^2+140.2961154*sin(.5773502693*x)/x^4-81.*cos(.5773502693*x)/x^3, diff(f[1, 0](x), x)+6.*f[1, 0](x)/x^5+1.500000000*f[1, 0](x)/x-1.*f[0, 0](x)/x = -15.58845727*sin(.5773502693*x)/x^2+25.98076212*sin(.5773502693*x)*(1/x^4)^(1/4)*exp(1/x^4)*GAMMA(.7500000000, 1/x^4)/x^2+140.2961154*sin(.5773502693*x)/x^4-233.8268591*sin(.5773502693*x)*(1/x^4)^(1/4)*exp(1/x^4)*GAMMA(.7500000000, 1/x^4)/x^4-81.*cos(.5773502693*x)/x^3+135.*cos(.5773502693*x)*(1/x^4)^(1/4)*exp(1/x^4)*GAMMA(.7500000000, 1/x^4)/x^3-20.78460970*sin(.5773502693*x)/x^6+6.000000004*cos(.5773502693*x)/x^5+62.35382908*sin(.5773502693*x)/x^8-36.00000002*cos(.5773502693*x)/x^7, f[0, 0](.1) = 1.503497680, f[1, 0](.1) = -.5011660086}

Following Preben Alsholm's suggestion from my previous thread I am using lsode[adamsfull], since no other method i have tried worked for this problem. I am currently using:

Sollsodefull:=dsolve({ODEs}, numeric, method = lsode[adamsfull])

and it seems to work. I am wondering if there is a way to optimize this, as I will be extending my problem to n and l much larger than order unity numbers, therefore my system will contain about 10^4-10^5 equations. Solving this symple system of 2 equations takes a bit less than a second, but still it takes some time for the processor on my MBP. I am affraid it will be a nightmare for the full problem. Whats the most optimal dsolve option for this kind of problem? Any ideas?

I have also attempted dverk78, rkf45,rosenbrock, lsode(without the adamsfull option), and all failed for this particular system. Errors were:

1. For rkf45: Error, (in f00) cannot evaluate the solution past the initial point, problem may be complex, initially singular or improperly set up

2. For dverk78: Error, (in Soldverk78) cannot evaluate the solution past .1, step size < hmin, problem may be singular or error tolerance may be too small

3. For rosenbrock: Error, (in dsolve/numeric/SC/firststep) unable to evaluate the partial derivatives of f(x,y) for stiff solution

4. For lsode without [adamsfull]: Error, (in Sollsode) an excessive amount of work (greater than mxstep) was done

5. For default method with stiff=true and inplicit=true options: Error, (in dsolve/numeric/SC/firststep) unable to evaluate the partial derivatives of f(x,y) for stiff solution

Dear all,

I want to use the Maple Compiler to improve the performance of some of my codes. To get used to it, I tried doing the examples from the ?Compiler help-page, but everytime I run the compiler, I get the error message:

"Error, (in Compiler:-Compile) compiler exited with nonzero status 1: 

Do some of you know a possible reason for this?

Thank you all.

Download test.mw

Hi
Please give me the matlab coding for plot together of attach figure by matlab.fig
thanks...!

Hello, 

is there a way I can use data (variables) from Maple environment in the Maplesim environment. 

I have a scirpt in maple that generates the robots joints angles and need to use them in the 3D robot built in maplesim. I know I can export/Import data, but this sounds redundant. Is there a way to simply use an input block as a source of the data in maplesim and have the variable name generated in maple used int. Similar to what Matlab/Simulink does.. 

thanks.

Могу ли я использовать Клен, чтобы найти конкретные решения, которые выражаются либо в начальных и эллиптических функций для систем обыкновенных дифференциальных уравнений. Например, вы можете получить в Maple решений (sub_Solve01, sub_Solve02) для систем, которые перечислены в файле?
exp01.mw

I have a system of pdes and solved numerically using pdsolve (numeric) command.

The system consists of four first order partial differentia equations.

for example u(x,t), R(x,t)....

what command should I give to the Maple and get the graph of u(x,t) at a specific point x_0?

For example, I need a plot for u(30,t).

Is it possible with the maple plot?

I really appreciate your help.

Thank you for reading this post. :)