Dr. Blake Martin

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6 years, 13 days
Senior Developer

MaplePrimes Activity

These are replies submitted by bmartin


Apologies for the delay in getting back!

Note that when the icon has a blue background that this is the "Display only probed variables" mode, otherwise it is in the "Display all model variables" mode. So I believe in your previous post the modes were mixed up, which is why for example TV11, TV12, and TV13 appear in the first image and not the second.


The state variables listed in the console output represent the required variables to perform the simulation (integration) - often a minimal set - whereas the variables in the "all model variables" section in the simulation results will generally be formed by the state variables as well as other quantities that were calculated (possibly from algebraic equations, definitions, ...).

If you believe you are experiencing a bug or would like some insight into what you are investigating you can always send an email to our technical support (!


Could you please provide details of what it is you are trying to do? As a note, not every user on MaplePrimes will have access to the document you linked to in your post, it is not from an open-access journal.


Another way of getting the result you want would be to do sqrt(2470.0). If you tell Maple that you have a float instead of an integer value, it will automatically calculate the result using floating-point arithmetic. 


Are you able to provide more information or some code that you've been working on? This would make it easier for the MaplePrimes community to help you with the question you have.


The code you've shared is quite lengthy, making it difficult to follow exactly what you are trying to do. If you are able to isolate the problem you are having to a shorter (preferrrably minimal) amount of code that produces your error, it will be easier for the MaplePrimes community to give you answers.


Maple has a similar utility with MPL files and are executed using the 'read' command. Here is a link to the Maplesoft online help where this file type is dicussed.




Thank you for providing the additional info and giving insight into the problem you are facing. Here are a couple Maple commands that will give you exactly what you are looking for!

s := [cos(t), sin(t)]; # define the position
v := diff(s, t);  # take the derivative to get velocity 
Nl := 30;  # number of lines to draw
plots:-display([seq(plot([op(subs(t=2*Pi*(N/Nl), s+q*~v)), q=-1..1]), N=1..Nl)]);

The last line of Maple code is the idea I had alluded to earlier. Let me try to break it down a bit for you. This chunk of code will create a single plot of the tangent line when t is a given value and varies q from -1 to 1.

plot([op(subs(t=2*Pi*(N/Nl), s+q*~v)), q=-1..1])

Using the 'seq' command, we can create a list of multiple plot structures, each for a different time t using the index N. I made t vary between 0 and 2*Pi. Then using the plots package I displayed all the lines at once. Here is the result:




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