Recall at k

$$R@k = |rel \cap top_k| / |rel|$$ Saturates at 1; unlike precision it cannot be raised by asking for a longer list than there are relevant items.

Usage

ColMet(pred_rank, relevant, k)

Arguments

pred_rank

Ranked item ids, best first.

relevant

Relevant item ids.

k

Cutoff rank.

Value

Named list with estimate, hits, k, n_relevant, method.

References

Standard IR metric; no single owning source.

Examples

ColMet(c(1, 2, 3, 4, 5), c(2, 4, 9), 3)
#> $estimate
#> [1] 0.3333333
#> 
#> $hits
#> [1] 1
#> 
#> $k
#> [1] 3
#> 
#> $n_relevant
#> [1] 3
#> 
#> $method
#> [1] "recall at k"
#>