Sequence and list with mixed object types

slik shared this problem 11 years ago

Answered

Hi,

list1={a,c} contains a segment (a) and arc (c)

Sequence[Element[list1,i],i,1,2] gives {a,?}

Zip[A,A,list1] something went wrong.

Simon

https://ggbm.at/553553

The same problem

Comments (4)

Zbynek ● 11 years ago

Hi, Element only works if all elements of the list are of the same type and we won't change that.

I doubt we can improve Zip in this way either (internally objects cannot change type, so we would have to create new objects all the time).

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slik ● 11 years ago

Thanks,

OK I was trying to use

2*Element[list1,f] where f is a slider

But Element[2*list1,f] works fine.

Simon

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Zbynek ● 11 years ago

Hi,

2*list1 converts everything with number value to numbers, so there is no problem with different types. So if you only want to pick the numeric values and ignore their geometrical meaning (area of polygon, length of segment, ...), you can use Element[1*list1,n] or Element[CopyFreeObject[list1],n].

Cheers,

Zbynek

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slik ● 11 years ago

Zbynek,

I found that 1*list1 doesn't work, but 2/2*list1 does. So does 0!*list1. :D

Simon

https://ggbm.at/553557

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