Interpolate categorical variables to switch at midpoint

Categorical variables like DECAYCD can't be linearly interpolated between inventory years. Instead, we assume they switch values at the midpoint (rounded down) between non-missing values. Trailing NAs are replaced with the last non-NA value and leading NAs are returned as-is.

Usage

step_interp(x)

Arguments

x

a vector

Value

a vector with no NAs

a vector

Examples

step_interp(c(NA, NA, "A", NA, NA, NA, "B", NA, NA, NA, NA, "C", NA))
#>  [1] NA  NA  "A" "A" "B" "B" "B" "B" "B" "C" "C" "C" "C"