Items tagged with eventsevents Tagged Items Feed

Plotting the Parameters that cause a...

October 08 2012 by Maple

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Hi,

So I've got a numerical solution to a D.E. and want to find which parameters (v, theta) cause the second event to occur. Here's my dsolve

> soln:= dsolve({eqx, eqy, inty, intx, x(0)=0, y(0)=0}, {x(t), y(t)}, numeric, method = rkf45, output=listprocedure, parameters=[v, theta], events=[ [ [diff(y(t),t)=0, y(t)

The first event is "Does the trajectory reach its max at a height less than 3.05m? If so, stop computation"...

Hi! I have the same problem.

Hi!

I have the same problem.

   "Simulation problem: maximum number of event iterations reached (100) at t= ...."


I have a model which worked without problem in maplesim2, using a lot of event iterations. The model can only work this way, becouse its a mechanic model where the friction is function of the sliding speed, thus where the speed changes value, the friction coefficient does also, and an event occurs.

I really need to know where...

What are events?

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What is meant by events? I have seen this error numerous times.

   "Simulation problem: maximum number of event iterations reached (100) at t= ...."


How do I model so that I can avoid them?

dsolve, events: how to build an efficient...

September 14 2011 by Maple

My question is related to this discussion on "querying events"

http://www.mapleprimes.com/questions/125273-Dsolve-Events-How-To-Control-For-A-Sign-Change#comment125426

I thought I might start a new thread.

The following loop is an illustration of the sort of thing I'd like to do with dsolve and events: I loop over a parameter of the "event" and extract information on the solution at different values of the parameter. Here is the code (successfully tested on Maple 15 / Standard / Windows)...

dsolve, events, how to control for a...

August 30 2011 by Maple

I have a system of 3 ODEs in 3 variables x(t),y(t),z(t) to be solved numerically. I would like to set up events to halt integration as soon as one of the derivatives changes sign.

I've tried things like:

'events' = [ [ diff(x(t),t) >0, 'halt'] ] :

'events' = [ [ diff(x(t),t) = 0 .. 0.1, 'halt'] ] :

I might have tried something like increasing(x(t)) (how nice and intuitive), but if I understand correctly the help page on this, increasing(x(t)...

Pushing dsolve to its limits

August 19 2011 by Maple 15

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And so with this provocative title, "pushing dsolve to its limits" I want to share some difficulties I've been having in doing just that. I'm looking at a dynamic system of 3 ODEs. The system has a continuum of stationary points along a line. For each point on the line, there exist a stable (center) manifold, also a line, such that the point may be approached from both directions. However, simulating the converging trajectory has proven difficult.

I have simulated as...

dsolve event handling question, general

June 02 2011 by Maple

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dsolve event handling looks like a great tool, but I can't understand how it works and it's not sufficiently popular to google my way to examples online. There are two things I'd like to do: 1) interrupt the computation once some variable leaves a certain range, 2) interrupt the computation if the solver gets stuck into an infinite loop. Both are documented in the help, but I don't understand it. Suggestions welcome, thanks!

http://www.maplesoft.com/support/help/Maple/view...

Program upgrade, model not working anymo...

March 13 2011 by Maple 14

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Hello!

I made an upgrade from Maple 13 to 14, but a program i wrote with maple 13 (ode event handling) simply is incorrect in maple 14. The events aren't recognized anymore. What is the problem?

Thank You.

ODE Event handling

February 10 2011 by Maple 13

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Hi!

I i have a 2nd order ODE where i want to chance the derivatives of x(t) and y(t) exactly at sqrt(x(t)^2+y(t)^2)=1 ,or before, as close to 1 as possible.

I found "event=" in/dsolve/numeric/events, where i can define the trigger and the action.

What is the difference between: "event=[[sqrt(...)-1,diff(x(t),t)=...],[sqrt(...)-1,diff(y(t),t)=...]]" and "event=[[sqrt(...)-1,[diff(x(t),t)=...,diff(y(t),t)=...]]]", because i get different results, which one is the correct form?

Raptor Math

August 05 2010 by Maple

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This describes in more detail (with permission and citation) the method posted here of solving problem 2 in the XKCD comic Substitute.

Making a dash for it

November 19 2009 by Maple

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An attempt at question 2 of the xkcd Velociraptor Math problem (mentioned on this blog post). The parameters and events facilities of

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