renest: Invert the nesting of a list-of-lists

In sethmcg/climod: Bias correction and other tools for climate model output

Description

Given a nested list, invert the nesting so that the inner list becomes the outer list and vice-versa. The structures of the elements of the inner lists are preserved. This function is more easily demonstrated than explained; see examples.

Usage

renest(lol)

Arguments

lol	a nested list.

Details

All inner lists must have the same length. The outer list of the result will use the names of the first inner list (if they exist); any other inner list names will be discarded.

Value

A nested list

Examples

f <- list(a=list(x=1, y=2, z=3), b=list(x="one", y="two", z="three"))
g <- list(x=list(a=1, b="one"), y=list(a=2, b="two"), z=list(a=3,b="three"))


print(str(f))
print(str(g))          
print(identical(g, renest(f)))


## Inner list elements may themselves be lists or other complex
## objects; they are left as-is.

i <- list(a=list(x=1, y=2, z=3),
          b=list(x=identity, y=seq(2), z=lapply(f,length)))

          
j <- list(x=list(a=1, b=identity),
          y=list(a=2, b=seq(2)),
          z=list(a=3, b=lapply(f,length)))

print(str(i))
print(str(j))          
print(identical(i, renest(j)))


## Names of inner lists after the first are ignored and discarded.

h <- list(a=list(x=1, y=2, z=3),
          b=list(i="one", j="two", k="three"),
          c=list(z=2, y=4, x=6))
str(h)
str(renest(h))

sethmcg/climod documentation built on Nov. 19, 2021, 11:12 p.m.