Hello folks,

I have to admit I am somewhat new in using maple as well as in this board. However I used the search engine and could not find the answer to my question.

I coded a little program that - among other things - should randomly draw one entry from a set of integers. Thus I use the function choose from the RandomTools package. From other software packages (for example stata) I know that usually one would set a seed for those pseudo random numbers to be...

This is in response to a Question about the speed and memory use of an animated DEplot. The problems are that the example's animation was slow to create, and prohibitively expensive to save in a Document.

An alternative approach is to combine multiple calls to plots:-odeplot with a call to plots:-fieldplot to supply the background flow arrows. This is a lot faster. It takes less memory to create and run, but the GUI may still consume too much resources saving it. The good news is that it's so much faster that it's not inconvenient to re-run the entire thing from scratch. And so it's quite feasible to remove all the expensive output from the Document prior to saving and thus avoid the whole resources problem.

The original questioner also wanted to visualize with resect to two varying parameters. So I've also done an implementation of that using Embedded Components and two Sliders.

Here is the old DEplot animation. It takes about 40 sec to create it animation on an Intel i7.

Here is the new combined odeplot+fieldplot animation. It takes a second or two to create its animation on an Intel i7.

Here is the DEplot in Embedded Components. It's very slow, and the image doesn't change smoothly with the sliders.

Here is the new combined odeplot+fieldplot in Embedded Components. Its image changes pretty smoothly with the sliders.

I encourage completely quitting the GUI (not just restart, or close Document and re-Open) between comparison runs of these implementations, of you want to get a really good feel for the effects of both running them as well as saving them (with and without all output).

For the Embedded Component documents, the functioning code resides inside the "initialize" button. (right-click, go to Component Properties, Action When Clicked, only if you want to inspect it.) To run those two  Documents, execute all the commands (use the triple-exclam from the menubar if you like), and then press the "initialize" button, and then move the sliders.

The difference in performance is related partly to the use of hardware datatype Arrays in the PLOT structures generated by odeplot and fieldplot. (But an `arrow` primitive would help even more!)

And (I think) there is improvement by virtue of using dsolve/numeric/parameters in the use of `odeplot`. That saves overhead from repeated cold invocations of dsolve/numeric. And DEplot doesn't support that, since it expects as argument the system of DEs and ICs. The newer `odeplot` command accepts the procedure returned by dsolve/numeric, and thus allows for efficient repeated setting of parameter values. The `fieldplot` command doesn't need the solution of the DE system at all: it just needs the DEs.

I would have considered wrapping the whole combined approach up into a single command, but it might have to accept separate options for the view ranges, in order to always look its best. A smart version might be able to deduce the computed ranges from the odeplot output, and then create the background fieldplot based on that.

Can anyone explain the method that was followed in "Box Discretization" scheme in Maple Help?

Am trying to discretize 4th order terms in space..... d^h/dX^4 and third and second order in the same way....

dsolve command doesn't work :(

it's very important =\

y*(dy/dx) + 2b*y*|y| + x*k^2 = 0

Dear guys! My question is: "how can I evaluate x when I fix y for an example equation y:=x+x^2". for each value of x we have a value for y. we can obtain it for example with "eval". but how about in this case?

Thanks

I have a maple exercise where it ask me to find the limit of a sum, here what's I type

f:= 2*k/(2*k+11);

g:= sum(f,k=1..n);

limit(n^(11/2)*g,n=infinity);

It spit out the answer infinity

but the answer is 10395/64*Pi^(1/2), can anyone tell me what am i doing wrong

   We have four points A, B, C, E, which form a convex polygon in the plane Π, and a point S, which doesn't belong to  Π. The points A, B, C, E, and S form a pyramid. The following distances are measured with some error: |AB|=2.9, |BC|=4.43, |CE|=5.10, |EA|=5.2, |AC|=2.29, |BE|=3.17, |SA|=3.77, |SB|=4.27, |SC|=3.66, and |SE|=4.36. In fact, there doesn't exist a pyramid with exactly these distances. The problem arises: to find the numbers XAB, XBC, XCE,...

Hey there, I am trying to plot R0 vs x with my output of a loop. Just wondering how I go about this and I am not very coding savvy, so my apologies. My code is below.

for Lambda from 40 to 80 do R0 := eval(R[0], {mu = m, delta = del, gamma = g, omega = o, d[1] = dk, d[2] = dc, alpha[1] = ak, alpha[2] = ac, beta[1] = b1, beta[3] = b3}); qq := eval(Y, {mu = m, delta = del, gamma = g, omega = o, d[1] = dk, d[2] = dc, alpha[1] = ak, alpha[2] = ac, beta[1] = b1, beta[3] = b3}...

Can one perform animation using the data file.

I want to animate the graph betweeen two variables say x and y, which I have stored in a data file. Does maple support any such operation?

So i need to plot 4*x-x*y^2 = 5 and (1/3)*x^3+y^2 = 1 between x = -10 .. 10, y = -10 .. 10.

I tried:

> f := 4*x-x*y^2 = 5;
                         
> g := (1/3)*x^3+y^2 = 1;
                       

   > plot({f, g}, x = -10 .. 10, y = -10 .. 10)

What did i do wrong?

Thanks

Hi,

I am using Maple 14 full eddition (not classic) to represent some equations. I require Maple to calculate the summ from 1 to n of the odd terms only. Below is what I have developed so far off all terms in the series.

Can anyone assist in changing it to odd terms only?

Kind regards,

John
Australia

In this post I will describe a little about the OU course MS325: Computer Algebra, Chaos and Simulations, which I took last year.

MS325 is a level 3 OU applied mathematics course, which means, roughly that it is pitched at the level of a final year mathematics undergraduate. It is split into three components: Computer Algebra, which teaches the use of Maple and Maple programming; Chaos, which teaches dynamical systems, deterministic chaos and fractals, with an emphasis...

The Magma package in Maple 15 includes the command IsSubMagma.  This tests whether a specified subset of a magma is closed under the binary operation that defines the magma.  For example, consider the following Cayley table for a group of order four.

> with( Magma ):
> m := << 1, 2, 3, 4 |

I've got Maple15 and was trying to use the new feature MarkovChain from Finance library. But I got the error Finance.dll not found. What am I supposed to do?

i want to integrate dbeta at the bottom of the following code, however, it said wrong number of argument. Why ? how to correct it the to integrate it successfully?

Af := ft + f1*dX + f2*dv + 1/2*f11*dXt + 1/2*f22*dvt + f12*dXvt;
Af := subs(dX = (miu - v/2)*dt, Af);
Af := subs(dv = a*(b - v)*dt, Af);
Af := subs( dXt = v*dt, Af);
Af := subs( dvt = v*(rho^2)*dt, Af);
Af := subs( dXvt = rho*p*v*dt, Af);

Af := subs( ft = (dalpha*y + dbeta)*f, Af);