BUG ! Solve APP failed ? [Solved]

[dg1969]

Hi,

Here is two functions:
\[x(t)=-\dfrac{a}{2\tan\alpha}\cdot\sin\left(\dfrac{2r\omega\sin\alpha}{a}\cdot t\right)\]

\[z(t)=-\dfrac{a}{2\tan\alpha}\left(1-\cos\left(\dfrac{2r\omega\sin\alpha}{a}\cdot t\right)\right)\]

I'd like to solve this problem of two equations and two unknows \(A,Y\)

\[x(A)=1000\]
\[z(A)=Y\]

with : \(a=520\); \(r=105\); \(\omega=-1\); \(\alpha=1,53\times10^{-3}\) all defined as global var in the prime

Code:


fsolve([VAG.X1(t)=1000 VAG.Y1(t)=y],[t y],[10 -5])

Give the answer in less than a second : [9.52 -2.94]

I have a "VAG App" based on parametric plot App and where I place \(x(t)\) and \(z(t)\) in X1(T) and Y1(T):

Code:


X1(T)=-a/(2*TAN(alpha))*SIN(2*r*omega*SIN(alpha)*T/a)
Y1(T)=-a/(2*TAN(alpha))*(1-COS(2*r*omega*SIN(alpha)*T/a))

In the symb view of solve APP I put :

Code:


E1: VAG.X1(A)=X
E2: VAG.Y1(A)=Y

And in the num view I place X:1000 (not selected) and the guess for two unknows (selected) A:9.5 ; Y: -2.9

But the solve APP always failled

Any idea, What's wrong ?

[tvarini]

Try:

X1(T)=(-a/(2*TAN(alpha)))*SIN((2*r*omega*SIN(alpha))/a)*T)
Y1(T)=(-a/(2*TAN(alpha)))*(1-COS((2*r*omega*SIN(alpha))/a)*T)

[dg1969]

Ok,
Thank for your answer "tvarini"... But I fact I find that the solve APP have a very strange behavior..

If I place in the solveAPP :

Code:


E1: VAG.X1(A)=X
E2: VAG.Y1(A)=Y

Then it is impossible to get a result on the num view... Only a warning message...

I have to press first (in the symb view) on the soft key "EVAL" to make appear explicitly expressions in term of global variables :

Code:


E1: -a/(2*TAN(alpha))*SIN(2*r*omega*SIN(alpha)*A/a)=X
E2: -a/(2*TAN(alpha))*(1-COS(2*r*omega*SIN(alpha)*A/a))=Y

In this way, in the num view (X=1000 uncheck; guess for A and Y checked) the result is OK... But Why such behavior?

From my point of view VAG.X1(T) and VAG.Y1(T) are perfectly valid and accessible from everywhere on the calc...

Who can explain ?

And now the bug (But I think it is already well known) :

If I place In the num view:

Code:


E1: VAG.X1(A)=1 000
E2: VAG.Y1(A)=Y

Note the small space in "1 000" (my choice for digit grouping in home setting... 123 456.789)

In this case the soft key "EVAL" has no effect (warning "!" in screen)...

Thank's for reading... Sorry for my very bad english....

[Tim Wessman]

Hello,

I followed your steps and it worked properly for me with the current public release (2015 6 17 r8151), even with the 1 000 space in there. That is using the X1(A)=X and Y1(A)=Y as you tried first.

Which version do you have on your side?

[dg1969]

Tim, thank you for taking time to read me...

(09-15-2015 09:46 PM)Tim Wessman Wrote:  I followed your steps and it worked properly for me with the current public release (2015 6 17 r8151), even with the 1 000 space in there. That is using the X1(A)=X and Y1(A)=Y as you tried first.

Which version do you have on your side?

Yes I use the latest firmware 2015 6 17 r8151 on prime and on emulator...



I will detail step by step with emulator screen captures (for me, the same problem occur on the emulator too)

1) I create global variables :


2) I create a copy of the parametric plot (named VAG) and write the two function of T:


3) Now I open the solve-app SYMB view and place the VAG.X1(A)=X and VAG.Y1(A)=Y:


4) But on the num view nothing is possible !


5) Only the explicit expressions are working (Here I use the EVAL soft key on symb view):


As you can see : With good guesses the good result :



And finally the "bug" for me: I can't use the EVAL soft key if I place "1 000" in place of "X" in the symb view... "!" in orange disk pop up for few second (I can't capture it)


I do my best to explain... I can send you backup or what ever you want if needed

Tkank's for reading !

[Tim Wessman]

Thanks, that is really close to what I did, but there are some small differences. I will step through and see if I can get the problem as well. Much appreciated!

[jebem]

(09-16-2015 07:08 PM)dg1969 Wrote:  Yes I use the latest firmware 2015 6 17 r8151 on prime and on emulator...



I will detail step by step with emulator screen captures (for me, the same problem occur on the emulator too)

1) I create global variables :


2) I create a copy of the parametric plot (named VAG) and write the two function of T:


3) Now I open the solve-app SYMB view and place the VAG.X1(A)=X and VAG.Y1(A)=Y:


4) But on the num view nothing is possible !


5) Only the explicit expressions are working (Here I use the EVAL soft key on symb view):


As you can see : With good guesses the good result :



And finally the "bug" for me: I can't use the EVAL soft key if I place "1 000" in place of "X" in the symb view... "!" in orange disk pop up for few second (I can't capture it)

Is it only me, or the pictures are not available anymore?

404 Not Found
Sorry, the requested page doesn't exist
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[ww63]

I can see the pic in both, the original post and your quote.

[DrD]

The pictures don't seem to exist on the server. The iconic version shows up in the post, but clicking on any of them returns a '404 - not found' message.

-Dale-

[dg1969]

I'm sorry for images... I chose the first free hosting images I found... Bad idea. Can you recommend a good address ?

Here is a copy of images in zip attached piece...

[ebswift]

(09-17-2015 06:53 PM)dg1969 Wrote:  I'm sorry for images... I chose the first free hosting images I found... Bad idea. Can you recommend a good address ?

Here is a copy of images in zip attached piece...

pasteall.org is a good community run place to share images and code, just select the image option to make the share.

[dg1969]

(09-18-2015 08:27 AM)ebswift Wrote:  pasteall.org is a good community run place to share images and code, just select the image option to make the share.

Thank's for your advice. I change the url's of all images now...