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we always have subscript variable in the math book, but how could this be natral done in maple

I want to get a seq aaa3

seq(a[i],i=1..3)

but how could I get a  aij

seq(a[i_j],i=1..3);

and

seq(a[ij],i=1..3);  both was not right

I'm trying to solve some ODE analitically. But Maple gives me an incorrect solution. What am I doing wrong? Thank you.

 

I am currently running into an issue where the numerical solution to an equation (involving an integral, yes, but the value I am solving for is simly a constant in the integral) is taking significantly longer than I would hope it would to solve. I am solving a similar equation (with a simpler expression) and it is significantly easier to solve, and I am hoping for that kind of speed.

On the last two lines in the attachment, I have two expressions. The penultimate expression is the baseline speed that I would like to match. The last expression is the fsolve I would like to speed up.

Is there any way to numerically speed up the process? I found that when I did tracelast after halting the process, there were HUGE numbers being added and subtracted, multiplied and divided. Not only did this significantly slow down the proecss but it also adds much numerical instability, which I would also like to avoid.

All help would be appreciated.

pole-dragging-mapleprimes.mw

how to compute non-reduced hilbert series?

hilbertseries return a simplified version of hilbert series,

 

how to output non-simplified version of hilbert series?

Hi there,

I've been trying to find an equivalent to MATLAB's unique command in Maple, but I had no success.

I've seen that Maple would return the elements that are either repeated (FindRepetitions) or not repeated (MakeUnique), but not the indices within the original list.

Is there way to do that?

Thanks,

jon

Hi, I installed Maple 17 a while back and was able to work all the commands but recently I reinstalled it
I tried a command which gave me an error that I never got before

>rightsum:=RiemannSum(1/x^2,x=50..75,partition=25,method=right,output=plot);


Error, (in Student:-Calculus1:-RiemannSum) external linking: error loading external library statshw.dll: The application has failed to start because its side-by-side configuration is incorrect. Please see the application event log or use the command-line sxstrace.exe tool for more detail.

When I tried to reinstall the only issue was that it had trouble installing Visual C++ 2005 redistribute however I already have it on my computer and I don't intend to uninstall it since it took a long time to actually get my other programs to have it working. Is there anyhting I can do to fix this error? (Plotting other stuff seems to work fine except for Riemann Sums)

Hi all,

I google and found a program using C# connect with Maple. The Maple file is mla file - a pakage library type of Maple. I want to review data structure and all interfaces funtions to understand the way to implement this features.

Please help me the way to read the original Maple code. I uploaded the .mla file into mediafire if you want to review it. Link http://www.mediafire.com/download/abd9kpk3q6oq8lb/CHEMISTRY.mla 

Regards,

Quan Nguyen

Hi there,

I'm trying to simulate an stochastic SIR model following the Gillespie algorithm, as described here [1].

 

When trying to update each process' probabilities, it looks like Maple is not updating their values. Although each element of the lists S, I and R is updated the ai lists are not updated.

For example, for a given index i

a2[i]:= m*S[i]:

takes the same value for every i, regardless of the value of S[i].

Can anybody tell why this is happening or what's wrong with the worksheet? This is the attempt: MaplePrimes_SIR_model_simulation_Gillespie_algorithm.mw

 

On the other hand, I tried making things more clear through a couple of procedures. However, when it comes to the point where a random number with an exponential distirbution is computed:

Rexp := RandomVariable(Exponential(mu)):

it looks like Maple is unable to evaluate mu. But having a look at the Variables explorer, it has a defined value, indeed.

So what's wrong in the worksheet? Thi is the attempt: MaplePrimes_SIR_model_simulation_Gillespie_algorithm.mw

 

Thanks,

jon

[1] http://www.biosym.uzh.ch/modules/models/ETHZ/StochasticSimulation/sir_stoch.xhtml

I just bought Maple Student edition. I won't allow me to validate myself and won't allow me to install the software unless I remove Java 8 and install the much older Java 6?!

Please help.

Hi! when i'm trying to solve, i get the following warning: Warning, solutions may have been lost.

The equations i'm trying to solve are as the following:

>A=0.1;

> D=0.19;

> eqns:={y^1.5-9/8*B^0.5*y+3/4*x*y^0.5-3/4*(Pi/3)^0.5*[1+(1+3/4*(Pi/3)*(B*(1+x^2))^0.5)*x^2]/(1+x^2)^0.5=0, Pi/2-3*D=8/3*y^3+x*y^2+4*B^0.5*[1/3*B*y^1.5-2/45*B^2.5-3/2*y^2.5]-9/2*B*(1/3*B*y-3/40*B^2-3/4*y^2)-3*x*B^0.5*[1/3*B*y^0.5-1/7*B^1.5-1/2*y^1.5],B=A/(1+x^2)};

> vars:={x,y,B};

> solve(eqns,vars);

Warning, solutions may have been lost

What am i doing wrong?

Many thanks!

Hi, all

I use INT to calculate multiple integration as below. It runs more than 20 hours without results. I wander is there any problem in my codes.

restart;
A := sin(k*Pi*(x-h*cos(theta))/a)*sin(l*Pi*(y-h*sin(theta))/b)*sin(k[0]*h)*sin(k*Pi*x/a)*sin(l*Pi*y/b);

W := evalf[5](int(int(int(int(A, h = 0 .. (x-a)/cos(theta)), theta = Pi+arctan((b-y)/(a-x)) .. 3*Pi*(1/2)), x = 0 .. a), y = 0 .. b, numeric))

 

Thanks

Why the disparity in the solution of P1 and P2? P1 uses finite difference while P2 uses midrich.

See them here P1.mw     and   P2.mw

Hello,

What is the combination key for zooming in/out on a Maple 3D graphic?

It seems I have forgotten... (CTRL+left mouse button does not work)

Thankx

JMC

Hi,

 

  Suppose I would like to use writedata for a series of files, e.g. test1.txt, test2.txt, test3.txt.  

I tried

***

a_min:=1;a_max:=3;
b_min:=1;b_max:=3;
A:=array(a_min..a_max,b_min..b_max);


for i from a_min to a_max do
  for j from b_min to b_max do 
     A[i,j]:=i*j;
  end do;
end do;

for i from 1 to 3 do
  file_name:=`test||i`;
  writedata[APPEND](file_name,A);
end do;

****

Seems "||" inside `` does not work, is there any robust solution for this issue? 

 

Thank you very much

 

I am trying to define a new typt and I am beating my head against the wall...

What I have working:

TypeTools:-AddType(Element,'record(l,R)');
 
This defines a type which I can then use in type(xpr,Element) to be false or true depending on whether xpr is a record containing (at least) entries l and R or not.

Now I want to define a type ExpandedLine that is a Vector of Element (Element in the sense above). In fact, in the context of my application I am willing to settle for ExpandedLine being a Vector of record.

Tried various approaches (and making sure Vector is in uneval quotes in the AddType statement) like:

TypeTools:-AddType(ExpandedLine,'Vector'(record));

and variations but no luck.

Any help is appreciated.

Mac Dude

 

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