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GeoGebra Topic Problem French

Chercher l'erreur ConvexHull

Noel Lambert shared this problem 5 months ago

Solved

Pourquoi dans le fichier attaché ConvexHull({A,B,C,D}) retourne un polygone erroné ?

Files: EnvConv.ggb

The same problem

Comments (12)

mathmagic ● 5 months ago

newly an update problem

move A

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Noel Lambert ● 5 months ago

exact, bien attrapé

et pourtant j'avais "secoué" la figure de R-W

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mathmagic ● 5 months ago

strange

open the file

move B

then move D around AC (note convexhull when A C D are aligned)

then move C

I think there is a bug when the points was created in aligned positions

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Rousseau-Wallon ● 5 months ago

an update problem mean this is normal ?

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rami ● 5 months ago

Depending on which person has the problem :wink:

(yes, sometime has update problems in GGB (for example Locus() )

then you can make a bug-report and/or a workaround)

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rami ● 5 months ago

When I look to this bug as black-box, then I see the following statements (in the attachment)

Files: EnvConvB.ggb

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rami ● 5 months ago

Workaround (with small difference between A and the corner of Convex-Hull)

Files: EnvConvD.ggb

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Rousseau-Wallon ● 5 months ago

if you zoom with the mouse then the problem disappear

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rami ● 5 months ago

Thanks, yes I see this (now) too.

Spekulation:

Moving A with the mouse follows a pixel unit.

This unit changes with the zoom.

This means that A can no longer be manually set to f with sufficient accuracy (?).

In this version this can be done with a new button.

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Another question is: what is the possible path or area of C.

But I think for the developer the hints in this version are good enough and far more than usual.

Files: EnvConvD3.ggb

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Michael Borcherds ● 4 months ago

Thanks, we've add a new algorithm for v525 which should work better

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Michael Borcherds ● 4 months ago

v525 online

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rami ● 4 months ago

Thanks, Its works!

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