Apply a boolean mask to a delayed matrix

Elements failing the predicate are replaced with fill at materialisation time.

Usage

d_where(x, predicate, fill = 0)

Arguments

x

A delarr.

predicate

A function or formula returning a logical matrix.

fill

Replacement value for elements where the predicate is FALSE.

Value

A delarr including the mask.

Examples

mat <- matrix(c(-1, 2, -3, 4, -5, 6), nrow = 2, ncol = 3)
darr <- delarr(mat)

# Replace negative values with 0
masked <- darr |> d_where(~ .x >= 0, fill = 0) |> collect()
masked
#>      [,1] [,2] [,3]
#> [1,]    0    0    0
#> [2,]    2    4    6

# Replace values below threshold with NA
filtered <- darr |> d_where(~ .x > 1, fill = NA) |> collect()
filtered
#>      [,1] [,2] [,3]
#> [1,]   NA   NA   NA
#> [2,]    2    4    6