[R] list() assigning the same value to two items

Thaler, Thorn, LAUSANNE, Applied Mathematics Thorn.Thaler at rdls.nestle.com
Mon Jun 21 11:30:15 CEST 2010

Hi everybody,

I'd like to have a list with two elements, where both elements have the same value:

z <- list(a=1, b=1)

If it happens, that I've to change the value, I've to assure that I change both. This is error prone. Hence, a better way to achieve this is to define:

tmp <- 1
z <- list(a=tmp, b=tmp)

Now, I'm wondering if it is possible to make this more compact:
z <- list(a=tmp<-1, b=tmp)

Both approaches have the side effect that a variable "tmp" is created. So is there a way to achieve the same thing without having to define an additional variable? Something like

z <- list(a=1, b=a)

or even 

z <- list(a=b=1)?

Both commands don't work of course, but I'm just curious whether this is possible in principle (a rather academic question I've to admit)

Thanks + BR,

Thorn Thaler
Applied Mathematics Group 
Nestlé Research Center
PO Box 44 
CH-1000 Lausanne 26, Switzerland
Phone: + 41 21 785 8220
Fax: + 41 21 785 8556

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