Limit values to exact multiples of .5 and replace other values with NA

I wondered how I can limit a vector of numerics to exact .5 steps. Rounding is not allowed. All values that are not exact multiples of .5 shall be replaced by NA (they are erroneous data entries).

I think my approach of conversion into character with sprintf and using a reprex to identify values that are not .[0|5]0$ is rather straight forward. However, I'm curious about other ideas.

x <- c(seq(0, 1.5, .5), .3, 1.01, 0.53)
x
#> [1] 0.00 0.50 1.00 1.50 0.30 1.01 0.53

## desired output
x[!grepl(".[0|5]0$", sprintf("%.2f", x))] <- NA
x
#> [1] 0.0 0.5 1.0 1.5  NA  NA  NA

CodePudding user response：

Just having posted it, I realised I could also use %%

x[!x%%.5 == 0] <- NA
x
#> [1] 0.0 0.5 1.0 1.5  NA  NA  NA

CodePudding user response：

Another possible solution:

ifelse((x-trunc(x)) %in% c(0.0, 0.5), x, NA)

#> [1] 0.0 0.5 1.0 1.5  NA  NA  NA