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Is there a way to implement list comprehension in R?
Like python:
sum([x for x in range(1000) if x % 3== 0 or x % 5== 0]) same in Haskell:
sum [x| x<-[1..1000-1], x`mod` 3 ==0 || x `mod` 5 ==0 ] What's the practical way to apply this in R?
Nick
293
Package provides Python-style list comprehensions for R. List comprehension expressions use usual loops ( for , while and repeat ) and usual if as list producers. Syntax is very similar to Python.
Actually, list comprehension is much clearer and faster than filter+lambda, but you can use whichever you find easier. The first thing is the function call overhead: as soon as you use a Python function (whether created by def or lambda) it is likely that the filter will be slower than the list comprehension.
The difference between Lambda and List Comprehension. List Comprehension is used to create lists, Lambda is function that can process like other functions and thus return values or lists.
List comprehension works with string lists also. The following creates a new list of strings that contains 'a'.
Something like this?
l <- 1:1000 sum(l[l %% 3 == 0 | l %% 5 == 0]) Yes, list comprehension is possible in R:
sum((1:1000)[(1:1000 %% 3) == 0 | (1:1000 %% 5) == 0]) If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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