MaplePrimes Questions and Posts

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I have created a document on my computer that runs normally in Maple 2024.1. However, when I upload this document to MaplePrimes, it shows an error or behaves unexpectedly. The document contains a system of differential equations, which I solved numerically and plotted, but the plots and equilibrium points do not display correctly after uploading.

 

When I run this code on my local machine, it works perfectly. However, after uploading the document to MaplePrimes, it does not run as expected. What could be causing this issue? Is there a known problem with Maple 2024.1 when uploading documents, or could there be a compatibility issue with MaplePrimes?

Any help or suggestions would be greatly appreciated. Thank you!

This project discusses the predator-prey system, particularly the Lotka-Volterra equations, which model the interaction between two species: prey and predators. Let's solve the Lotka-Volterra equations numerically and visualize the results.

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alpha := 1.0; beta := .1; g := 1.5; delta := 0.75e-1; ode1 := diff(x(t), t) = alpha*x(t)-beta*x(t)*y(t); ode2 := diff(y(t), t) = delta*x(t)*y(t)-g*y(t); eq1 := -beta*x*y+alpha*x = 0; eq2 := delta*x*y-g*y = 0; equilibria := solve({eq1, eq2}, {x, y}); print("Equilibrium Points: ", equilibria); initial_conditions := x(0) = 40, y(0) = 9; sol := dsolve({ode1, ode2, initial_conditions}, {x(t), y(t)}, numeric); eq_points := [seq([rhs(eq[1]), rhs(eq[2])], `in`(eq, equilibria))]

[[0., 0.], [20., 10.]]

(1)

plots[odeplot](sol, [[t, x(t)], [t, y(t)]], t = 0 .. 100, legend = ["Rabbits", "Wolves"], title = "Prey-Predator Dynamics", labels = ["Time", "Population"])

 

``

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sol_plot := plots:-odeplot(sol, [[x(t), y(t)]], 0 .. 100, color = "blue"); equilibrium_plot := plots:-pointplot(eq_points, color = "red", symbol = solidcircle, symbolsize = 15); plots:-display([sol_plot, equilibrium_plot], title = "Phase Portrait with Equilibrium Points", labels = ["Rabbits", "Wolves"])

 

Now, we need to handle a modified version of the Lotka-Volterra equations. These modified equations incorporate logistic growth fot the prey population.

 

 

restart

alpha := 1.0; beta := .1; g := 1.5; delta := 0.75e-1; k := 100; ode1 := diff(x(t), t) = alpha*x(t)*(1-x(t)/k)-beta*x(t)*y(t); ode2 := diff(y(t), t) = delta*x(t)*y(t)-g*y(t); eq1 := alpha*x*(1-x/k)-beta*x*y = 0; eq2 := delta*x*y-g*y = 0; equilibria := solve({eq1, eq2}, {x, y}); print("Equilibrium Points: ", equilibria); initial_conditions := x(0) = 40, y(0) = 9; sol := dsolve({ode1, ode2, initial_conditions}, {x(t), y(t)}, numeric); eq_points := [seq([rhs(eq[1]), rhs(eq[2])], `in`(eq, equilibria))]

[[0., 0.], [100., 0.], [20., 8.]]

(2)

plots[odeplot](sol, [[t, x(t)], [t, y(t)]], t = 0 .. 100, legend = ["Rabbits", "Wolves"], title = "Prey-Predator Dynamics", labels = ["Time", "Population"])

 

``

 

 

plots:-odeplot(sol, [[x(t), y(t)]], 0 .. 50, color = "blue"); equilibrium_plot := plots:-pointplot(eq_points, color = "red", symbol = solidcircle, symbolsize = 15); plots:-display([plots:-odeplot(sol, [[x(t), y(t)]], 0 .. 50, color = "blue"), equilibrium_plot], title = "Phase Portrait with Equilibrium Points", labels = ["Rabbits", "Wolves"])

 

NULL


 

Download predator_prey.mw

If I'm not mistaken Mapleprimes doesn't accept m files nor folders.

TIA

When I began posting replies or answers in Mapleprimes I remember Carl Love explaining me the difference between them.
I was a newbie by then but I think I've grown up and now I know the difference between a reply and a comment.
For reasons of my own, which I will perhaps explain in a post one day, I have decided to sent only comments and no more answers.

Unfortuntely administrators, or maybe a robot, keep turning my comments into answers.
Which in turn forces me to convert these answers into comments, which are then converted back into answers... which may never end and is a complite waste of time.

Is there a way to declare that I want my choices to be respected?

(For the record I've even written in the header of my comment that I didn't want it to be converted into an answer, but the comment was removed and the conversion done !)

This is an extremely common situation; either some moderator displaced or deleted the question, or the OP deleted himself (herself).
Whatever the reason, it's always extremely upsetting to be confronted with this situation, which shows how rude, to put it mildly, some people can be.

Initial question (this day, about 2 hours ago)

Comment

I noticed tags on the post  

https://mapleprimes.com/questions/238161-Why-Maple-Gives-Solution-To-Euler-Ode

keep disappearing. 

I added tags "differential equation" and "dsolve" and so on.  

Later on when I visit this site again I found the tags are all gone.

Why does Mapleprimes remove the tags on post?

Or is someone else removing the tags? If so, why? is something wrong with the tags I've added?

This happend twice on this one post. I noticed earlier today the tags were gone, so I added them again. And now I see the same thing. They are all gone.

I have noticed over a few questions I have asked recently.
I ask a question.                   It goes to top of active converstaions
Some  one answers                                            "

I Reply                                                                *

A bit of time passes  so slides  of the top six/seven that show

Another Reply/Answer from someone                possibly does not show in active conversations.  I catch this by the orange flag or email notification

I reply                                 Does not appear in active conversations..

       This can kill the conversation chain.

I have even tried changing one of me replys to an answer but did not go to top active conversations again.

Has anyone else expperienced this?  

What is the result of this system command:


This is a bit long. What is the explanation here?

I asked a question a while ago

https://www.mapleprimes.com/questions/235734-How-Can-The-Functional-Derivativevariation

Which did not get any immediate responses but one late one which i had replied to, but nothing else since then. 

Is it appropriate to delete and repost and try to get more responses/exposure and see if anyone else has any ideas? 

Since @ecterrab is the one who responded I consider this an interesting problem that I would like to continue discussing. 

I started a thread about maplev-mode on March 1, 2024.

Joe Riel replied.

A couple days later, I attempted to reply to Joe's question. The blue 'Submit' bar continued to flash, never stopping.

I asked this question a few days ago, but, it was deleted as 'Spam'.

This is not spam.

Tom Dean

For the past days I observe that reply to posts stucks at the progess bar

(using a firefox browser). I am wondering whether that is only on my installation. Loading pages is not slow as reported here. I have a suspicion that this happens after having previewed a reply before submission. I observe also sometimes a yellow background of the preview and sometimes a blue background.

I try to submit now with blue backgound

Has anyone else noticed that Mapleprimes response/loading/refreshing time has become relatively much slower in the past few weeks?

I was about to update an older discussion with the information that the context pannel now contains an entry "Normalized Expanded".

I only remember that I was participating with another user.

So, I tried C_R AND other_user in the search field. This gives an error.

A space as an implict AND operator does also not work.

Happy new year everyone. Instead on making my usual new year resolutions, I though I would put up a request for some helpful  improvements here.

1) Please make search work properly. Allow searches to target specific sections. Posts, Questions, My own account, Other users. etc,

2) Add links to Maple help. Is there an online way of viewing Maple document? Or build Maple viewer into this site.

3) Add links to Maple Learn.

I just got an email saying a maple primes moderator deleted my question as 'SPAM'. It was not remotely SPAM but a strraight forward question about how to determine lengths of lines drawn in Maple Sketcher. 

The email tells me and gives me a link to 'contact' but it's not clear which of the many possible contacts listed to use!

Here's the email:

Your MaplePrimes post Length of a line drawn in Sketcher? was deleted by a moderator for the following reason: Spam. If you believe this was done in error, please contact Maplesoft customer service: https://www.maplesoft.com/contact.

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