# Possible bug : curve undefined

cooooldog shared this question 6 years ago

In order to create the following animated GIF:

I uses the following GGB:

When you open the GGB, and enable animation for slider f, you will find both curves h and i become "undefined".

By copying

r=If[5 > f > 0, 2^(4(5 - f) / 5) + 1, If[f ≥ 5, 2, ? ]]

but, i don't anderstand your algorithm...

choose a value for ?

I try to modifie ? to k ( slider)

and it's ok (?)

https://ggbm.at/569357

1

First, when I initially created the curve via

Curve[r cos(v) - r + 2 + cos(v) (1 + sin(5r (π / r + v))), r sin(v) + sin(v) (1 + sin(5r (π / r + v))), v, -2π / r, 2π / r]

without closing and re-openning the GGB, then it worked successfully in obtaining the GIF;

So there should be no problem in either the slider or the algorithm;

second, I tried to edit the objective properties of the curve, by adding "f>=0" to "condition to show object" in Advanced tab, it seems the problem disappears: even I close and reopen the GGB, there is no "curve undefined" problem any more. Or the "condition to show object" in Advanced tab would disappear when curve becomes undefined!

So still I think this might be a bug.

Hi,

it doesn't work because r is not defined for all values of f :

r=If[5 > f > 0, 2^(4(5 - f) / 5) + 1, If[f ≥ 5, 2, ? ]]

but, i don't anderstand your algorithm...

choose a value for ?

I try to modifie ? to k ( slider)

and it's ok (?)

1

Try to see the attached GGB which I modified the "Condition to show object" options of the two parametric curves, under the Advanced Tab of Object Propertes.

Nothing else changed

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