Sequence of Values in Regular Increments

Extracts a sequence of values from a vector in regular increments.

every(x, step = 2, start = 1)

every(x, step = 2, start = 1) <- value

Arguments

x

A vector of values.

step

The size of the increment between indices in the sequence.

start

The index at which to start the sequence.

value

A vector of new values to assign to x at the sequence of indices.

Value

A vector of values extracted from x.

Examples

# Extract every other value
# at odd positions
every(1:10)
#> [1] 1 3 5 7 9
# Extract every other value
# at even positions
every(1:10, , 2) # Note double commas
#> [1]  2  4  6  8 10

# Extract every 3rd value starting
# from 6th position
every(1:12, 3, 6)
#> [1]  6  9 12

# Replace values at even
# positions with 0
x <- 1:10
every(x, , 2) <- 0
x
#>  [1] 1 0 3 0 5 0 7 0 9 0