Spline instability

hawe shared this problem 9 months ago
New

Betrifft https://www.geogebra.org/m/zd9qbtrx

Inputbox Fig writes a point list to FigO

Inputbox Grid writes a index list to Grid

Grid holds a list of index numbers of the points from FigO that belong to a spline curve.

There a 10 Sliders to manipulate the transformation point lists FigO->FigDT and spline lists FigOShape -> FigDTShape

Dealing with the transformation sliders always reaches the point where the spline lists disappear - no undo possible.

Does it make sense to save a file with disappeared spline-list FigDTShape for debugging for you? See attached file if it is interesting to you...

Comments (11)

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I added a gif presentation of the transformations to the activity page.

almost in the last picture (1:03) you can see how the spline disappears, just as i was setting up the initial setting 0.0 ....

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Please say what you did exactly

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Please see gif-presentation.

https://www.geogebra.org/re...


I showed the effect of each slider and reset the last one to 1 with button [0.0] and the splines (blue figure) were gone.


Refers to the list variable FigDTShape (vanished without a trace. no undo possible).

There are 2 list variables with splines FigOShape static and FigDTShape moved by sliders.

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Be sure that there are no points moved to the same point. You can use unique() in lists of splines

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Sorry, what's wrong with https://www.geogebra.org/re... ?

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The list variable of the splines disappears just in the moment when I set it back to the initial position, SetValue(), this should not be the case...

And if such a case should apply, then the spline in question should be undefined and not the whole list disappear?


It seems that after a certain number of (re)calculations a critical point is reached - often the spline list disappears when expanding the list of the input box (FigO), as the new added points are not yet included in splines. Of course the splines has been recalculated because the pointlist was updated.

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The list variable of the splines...
What's the variable name?

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There are 2 List of splines

FigOShape is static based on points FigO (bound to Inputbox Fig) and FigDTShape based on transformed point list FigDT - FigDTShape used to terminate the collaboration after a while...

The last image of the AniGif shows the loss of FigDTShape, the blue figure is gone. And FigDTShape was never seen again.

/JT+Eds1PvRIAAAAASUVORK5CYII=


additional information

it's that time again, i get NO notification for new comments

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A try to see how BezierCurves behave

https://www.geogebra.org/m/ygawefgc

seems to have the same problem. I made a slider k to manipulate the nodes and control points of the curve. after some changes (sometimes very fast, sometimes after more extensive changes) the variable BezierCurve, list of Curve() of 16 Point Spline, disappeared.

when i look at the function list BezierCurve in CAS i get very strange stuff (big numbers)

/wAAAABJRU5ErkJggg==


BTW: what about to implement Bezier-Curves (Giac as I see can 7.15 Bezier curves: bezier )

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Ich hab einen neuen Fall mit verschwundenen Listen.


Michael, bist Du an weiteren Berichten oder Fallbeispielen interessiert?

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Yes, if it's simple and reproducible


Probably not if it just has lists that get too long :)

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