Created
February 21, 2017 23:52
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hack version of dplyr::mutate which preserves custom attributes
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| mutate_with_attrs <- function(df, ...) { | |
| olddf <- df | |
| newdf <- mutate(df, ...) | |
| newnames <- setdiff(names(attributes(olddf)), names(attributes(newdf))) | |
| sapply(seq_along(newnames), function(x) attr(newdf, newnames[x]) <<- attr(olddf, newnames[x])) | |
| return(newdf) | |
| } | |
| library(dplyr) | |
| mydf <- mtcars | |
| attr(mydf, "a") <- "x" | |
| attr(mydf, "b") <- "y" | |
| str(mydf) | |
| #> 'data.frame': 32 obs. of 11 variables: | |
| #> $ mpg : num 21 21 22.8 21.4 18.7 18.1 14.3 24.4 22.8 19.2 ... | |
| #> $ cyl : num 6 6 4 6 8 6 8 4 4 6 ... | |
| #> $ disp: num 160 160 108 258 360 ... | |
| #> $ hp : num 110 110 93 110 175 105 245 62 95 123 ... | |
| #> $ drat: num 3.9 3.9 3.85 3.08 3.15 2.76 3.21 3.69 3.92 3.92 ... | |
| #> $ wt : num 2.62 2.88 2.32 3.21 3.44 ... | |
| #> $ qsec: num 16.5 17 18.6 19.4 17 ... | |
| #> $ vs : num 0 0 1 1 0 1 0 1 1 1 ... | |
| #> $ am : num 1 1 1 0 0 0 0 0 0 0 ... | |
| #> $ gear: num 4 4 4 3 3 3 3 4 4 4 ... | |
| #> $ carb: num 4 4 1 1 2 1 4 2 2 4 ... | |
| #> - attr(*, "a")= chr "x" | |
| #> - attr(*, "b")= chr "y" | |
| ## no custom attributes | |
| mydf %>% mutate(z = 1) %>% str | |
| #> 'data.frame': 32 obs. of 12 variables: | |
| #> $ mpg : num 21 21 22.8 21.4 18.7 18.1 14.3 24.4 22.8 19.2 ... | |
| #> $ cyl : num 6 6 4 6 8 6 8 4 4 6 ... | |
| #> $ disp: num 160 160 108 258 360 ... | |
| #> $ hp : num 110 110 93 110 175 105 245 62 95 123 ... | |
| #> $ drat: num 3.9 3.9 3.85 3.08 3.15 2.76 3.21 3.69 3.92 3.92 ... | |
| #> $ wt : num 2.62 2.88 2.32 3.21 3.44 ... | |
| #> $ qsec: num 16.5 17 18.6 19.4 17 ... | |
| #> $ vs : num 0 0 1 1 0 1 0 1 1 1 ... | |
| #> $ am : num 1 1 1 0 0 0 0 0 0 0 ... | |
| #> $ gear: num 4 4 4 3 3 3 3 4 4 4 ... | |
| #> $ carb: num 4 4 1 1 2 1 4 2 2 4 ... | |
| #> $ z : num 1 1 1 1 1 1 1 1 1 1 ... | |
| ## preserves custom attributes | |
| mydf %>% mutate_with_attrs(z = 1) %>% str | |
| #> 'data.frame': 32 obs. of 12 variables: | |
| #> $ mpg : num 21 21 22.8 21.4 18.7 18.1 14.3 24.4 22.8 19.2 ... | |
| #> $ cyl : num 6 6 4 6 8 6 8 4 4 6 ... | |
| #> $ disp: num 160 160 108 258 360 ... | |
| #> $ hp : num 110 110 93 110 175 105 245 62 95 123 ... | |
| #> $ drat: num 3.9 3.9 3.85 3.08 3.15 2.76 3.21 3.69 3.92 3.92 ... | |
| #> $ wt : num 2.62 2.88 2.32 3.21 3.44 ... | |
| #> $ qsec: num 16.5 17 18.6 19.4 17 ... | |
| #> $ vs : num 0 0 1 1 0 1 0 1 1 1 ... | |
| #> $ am : num 1 1 1 0 0 0 0 0 0 0 ... | |
| #> $ gear: num 4 4 4 3 3 3 3 4 4 4 ... | |
| #> $ carb: num 4 4 1 1 2 1 4 2 2 4 ... | |
| #> $ z : num 1 1 1 1 1 1 1 1 1 1 ... | |
| #> - attr(*, "a")= chr "x" | |
| #> - attr(*, "b")= chr "y" |
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