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Hello,

I am quite new on Maple and Maplesim. A co-worker and I are evaluating a demo version (Maple 18 with Maplesim 7) for a possible purchase in 2015. For the project my collegue and I are working on, we need to detect when a signal becomes zero in order to switch between two options. We were trying to do this using the "Change" or "Boolean Change" components (the difference between those two is not really clear to us). Correct me if I am wrong, but those components should detect when a boolean signal has a change in value (both rising or decreasing) and in that case the output should become TRUE, while otherwise is FALSE.

The problem is that the component work if a "Terminate" is connected, but the output is always FALSE in any other case.

At the bottom we are attaching a file with two very easy examples.

In the first one the input of the "Boolean Change" component is a "Boolean Pulse". We compared also the output of the "Change", "Rising Edge", and "Edge with Initial Value" components. We were expecting istantaneous pulse with frequency equal to that of the boolean pulse, or its half for the Edge block. On the contrary the output of all the components stays zero (thus FALSE) for the whole simulation.

The second example use the output of a "Greater Threshold" component to enter the "Boolean Change", whose output is used to trigger a "Switch", whose output is in turn used as an input for the "Greater Threshold" component. The expected result is to have the "Switch" output to alternate the two inputs, instead it keeps the second one (thus the input for the switch is always FALSE).
The feature we need is more similar to this second output, but we don't understand what we are doing wrong or if there is another way to do it.
Thank you in advance
Irene

test_change.msim

calculs using Maple...

November 01 2014 sarra 215

Dear all;

Thank you very much is you can make the computation using maple.

I have this system:

x'(t)=x*y-x^2*y+y^3;

y'(t)=y^2+x^3-x*y^2;

I would like to make to change the system in another system using polar coordinate: like x=r*cos(theta) and y=r*sin(theta), and then derive a simple system: r'=F(r, theta) and theta'=G(r, theta), where here F and G are two unknowns functions. 

Many thinks if someone can help me using a Maple code. 

 

I have used the command "op" in a code that I have written with Maple 17. When I restart the maple server and run the whole code again, the result of the "op" command changes! why is this happening?

How to identify whether biased game is changed based on the latest toss from a sequence

can HMM identify this?

for example

if

fair fair fair biased biased fair fair biased

Hi,

When I run two times my code, the results change.

Have you any idea, why???

 

 

assuming a equations likes this:

tan(x)+y*sin(x)=1;

tan(x)-y*sin(x)=0;

I want to solve this equations using LinearSolve function(do not use solve()). I  fisrtly change tan(x)=u,y*sin(x)=v and then solve u,v using LinearSolve. finally, I obtain x=atan(u), y=v/sin(x).

the question is how can I perform the above operates neatly? I know I can achive this by using a lot of subs().but is there any tools in maple do this neatly just like IntegrationTools[Change]?

I'm simplifying this Reynolds Equation starting from here:

Reynolds:=Diff(p(x)*h(x)^3/(12*mu)*Diff(p(x),x),x)-u(x)/2*Diff(p(x)*h(x),x)+Diff(p(x)*h(x)^3/(12*mu)*Diff(p(x),z),z)=Diff(p(x)*h(x),t):

 

Then I apply the dchange command:

dchange({p(x)=P(X)*Pa,x=Lx*X,h(x)=H(X)*h2},Reynolds,{P,h,X,u,H});

 

The problem is that it expands the new derivatives and I need the equation in its compact form.

How do I tel Maple only to make the substitution but not to expand the result?

I know that it expands by default, can I modify that?

 

 

 

 

 

I have equation like :

 

 

 

Now I compute second derivative of F respect to x( u and w are functions of x,y):

 

 

 

I must change variables x and y so define them as function of r and s:

 

 

 

And my problem is I want change partial derivative of F respect to x to partial derivative of f respect to r and s. Can anybody help me ?

 

Hello,

I was wondering how (or what is the best way) to write a worksheet in which a change of formula is used when a certain value on the y-axis is reached.

So for example: if there is a mass-spring system with damping in it, I would like to change the value of the damping when the displacement/velocity/acceleration has reached a certain value.
So when I apply a force to the mass-spring system, and the acceleration for example is LOWER than 0.2 m/s^2 I use a value of X % damping, but when the value of the acceleration is HIGER than 0.2 m/s^2 I want to apply Y % damping. So in time the curve will increase (when low damping is used) and the curve will decrease (because high damping is used, because the y-value is higher than 0.2 m/s^2), and so on...

I hope somebody has a 'simple' idea. I know what I want to do, but I don't know how to put this down in a formula which I can write in Maple.

Greetings,
Frank

Dear All,

I need your help, what function in Maple must be used to find the different form of this function

f := product((p*beta[1]*(t[i]/theta[1])^(beta[1]-1)*exp(-(t[i]/theta[1])^beta[1])/theta[1])^Y[i]*((1-p)*beta[2]*(t[i]/theta[2])^(beta[2]-1)*exp(-(t[i]/theta[2])^beta[2])/theta[2])^(1-Y[i]), i = 1 .. n)

into this function

I've several versions behind but I getting a strange behavior. I created an assignment using the eco0 question bank. Later this assignment was passed to a class a semester later. The question bank eco0 was updated. As the instructor, using the review button on the assignment shows the new version of the question bank. As a student, the assignments are getting the old question bank question.  The students didn't start the assignment until after the questionbank change.(I think I'm using version 4.0.) 

Hi everybody,

Does somebody has an idea about how to model the temperature of water during freezing ?

I mean, if you consider a certain mass of water and you put it, for example on a fridge. I don't consider the convection but only the diffusion, and I would like to model, if possible with an animation the temperature of the water (as a cube for the shape).

Normally, during the freezing I should observe a decrease of the temperature, then a freezing...

Hi maplers

I was wondering if it is possible to change default document template and startup code?

/Delkrak

How to change font there?

 

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Debugger window

How to change "Scaling" in order to during "zoom in" coordinates x and y zoomed in user defined way?

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