R help - Jun 2005 - Dynamic Dictionary Data Type?

Hello!

I have an algorithm which performs lengthy operations and I would like to
cache results.  Other languages usually offer a dictionary data type
which I can use as an efficient way to dynamically cache already
calculated results - what's the best way to do this in R?

Best wishes,

Sven C. Koehler

> cache results.  Other languages usually offer a dictionary data type
> which I can use as an efficient way to dynamically cache already
> calculated results - what's the best way to do this in R?
It really depends on what sort of data you want to cache - if it is
fundamentally 1D, use a vector, 2D use a matrix etc.  The closest
equivalent to dictionary/hashmap is a list - however R's pass a copy
semantics might slow things down if you are caching a lot of data.

Hadley Wickham
http://had.co.nz

AFAIK R does copy-on-modify, so if you call f(aList, ...) and inside f()
aList is not modified, then a copy is not really made.

Andy
> From: hadley wickham
> 
> > cache results.  Other languages usually offer a dictionary data type
> > which I can use as an efficient way to dynamically cache already
> > calculated results - what's the best way to do this in R?
> 
> It really depends on what sort of data you want to cache - if it is
> fundamentally 1D, use a vector, 2D use a matrix etc.  The closest
> equivalent to dictionary/hashmap is a list - however R's pass a copy
> semantics might slow things down if you are caching a lot of data.
> 
> Hadley Wickham
> http://had.co.nz
> 
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