Calculate pairwise distances between each pair of items in a list

naivePairwiseDist(list, fun = jaccardIndex)

Arguments

list: A list
fun: A function that receives two vectors (such as jaccardIndex) and returns a number (scale)

Value

A symmetric matrix of dimension mxm, where m is the length of the list

This function is inefficient compared with matrix-based methods. It is exported just for education and for verifying results of matrix-based methods.

Examples


myList <- list(first=LETTERS[3:5], second=LETTERS[1:3], third=LETTERS[1:5], fourth=LETTERS[6:10])
naivePairwiseDist(myList, fun=jaccardIndex)
#>        first second third fourth
#> first    1.0    0.2   0.6      0
#> second   0.2    1.0   0.6      0
#> third    0.6    0.6   1.0      0
#> fourth   0.0    0.0   0.0      1
## despite of the name, any function that returns a number can work
naivePairwiseDist(myList, fun=jaccardDistance)
#>        first second third fourth
#> first    0.0    0.8   0.4      1
#> second   0.8    0.0   0.4      1
#> third    0.4    0.4   0.0      1
#> fourth   1.0    1.0   1.0      0