I use the mtcars dataframe and I use the following code to assign NA to all the values of columns drat and wt <=3.
df <- mtcars %>%
mutate(across(c(drat, wt), ~ifelse(.x<=3, NA, .x)))
How can I modify the code in a way that let me to assign NA also to the values of the column qsec if the value of drat or wt in the same row is <=3? At the end I want that each row where drat or wt is NA has NA also in the column qsec. Thanks
CodePudding user response：
We may use if_any on the columns that are changed to NA to return a logical vector to replace values in 'qsec'
library(dplyr)
mtcars1 <- mtcars %>%
mutate(across(c(drat, wt), ~ifelse(.x<=3, NA, .x)),
qsec = ifelse(if_any(c(drat, wt), is.na), NA, qsec))
-output
> head(mtcars1)
mpg cyl disp hp drat wt qsec vs am gear carb
Mazda RX4 21.0 6 160 110 3.90 NA NA 0 1 4 4
Mazda RX4 Wag 21.0 6 160 110 3.90 NA NA 0 1 4 4
Datsun 710 22.8 4 108 93 3.85 NA NA 1 1 4 1
Hornet 4 Drive 21.4 6 258 110 3.08 3.215 19.44 1 0 3 1
Hornet Sportabout 18.7 8 360 175 3.15 3.440 17.02 0 0 3 2
Valiant 18.1 6 225 105 NA 3.460 NA 1 0 3 1
CodePudding user response：
1) dplyr Continue the mutate to set qsec to NA if either drat or wt is NA. (If you meant and rather than or then replace | with & .)
mtcars %>%
mutate(across(c(drat, wt), ~ifelse(.x<=3, NA, .x)),
qsec = ifelse(is.na(drat) | is.na(wt), NA, qsec))
giving:
mpg cyl disp hp drat wt qsec vs am gear carb
Mazda RX4 21.0 6 160.0 110 3.90 NA NA 0 1 4 4
Mazda RX4 Wag 21.0 6 160.0 110 3.90 NA NA 0 1 4 4
Datsun 710 22.8 4 108.0 93 3.85 NA NA 1 1 4 1
Hornet 4 Drive 21.4 6 258.0 110 3.08 3.215 19.44 1 0 3 1
Hornet Sportabout 18.7 8 360.0 175 3.15 3.440 17.02 0 0 3 2
Valiant 18.1 6 225.0 105 NA 3.460 NA 1 0 3 1
Duster 360 14.3 8 360.0 245 3.21 3.570 15.84 0 0 3 4
Merc 240D 24.4 4 146.7 62 3.69 3.190 20.00 1 0 4 2
Merc 230 22.8 4 140.8 95 3.92 3.150 22.90 1 0 4 2
Merc 280 19.2 6 167.6 123 3.92 3.440 18.30 1 0 4 4
Merc 280C 17.8 6 167.6 123 3.92 3.440 18.90 1 0 4 4
Merc 450SE 16.4 8 275.8 180 3.07 4.070 17.40 0 0 3 3
Merc 450SL 17.3 8 275.8 180 3.07 3.730 17.60 0 0 3 3
Merc 450SLC 15.2 8 275.8 180 3.07 3.780 18.00 0 0 3 3
Cadillac Fleetwood 10.4 8 472.0 205 NA 5.250 NA 0 0 3 4
Lincoln Continental 10.4 8 460.0 215 NA 5.424 NA 0 0 3 4
Chrysler Imperial 14.7 8 440.0 230 3.23 5.345 17.42 0 0 3 4
Fiat 128 32.4 4 78.7 66 4.08 NA NA 1 1 4 1
Honda Civic 30.4 4 75.7 52 4.93 NA NA 1 1 4 2
Toyota Corolla 33.9 4 71.1 65 4.22 NA NA 1 1 4 1
Toyota Corona 21.5 4 120.1 97 3.70 NA NA 1 0 3 1
Dodge Challenger 15.5 8 318.0 150 NA 3.520 NA 0 0 3 2
AMC Javelin 15.2 8 304.0 150 3.15 3.435 17.30 0 0 3 2
Camaro Z28 13.3 8 350.0 245 3.73 3.840 15.41 0 0 3 4
Pontiac Firebird 19.2 8 400.0 175 3.08 3.845 17.05 0 0 3 2
Fiat X1-9 27.3 4 79.0 66 4.08 NA NA 1 1 4 1
Porsche 914-2 26.0 4 120.3 91 4.43 NA NA 0 1 5 2
Lotus Europa 30.4 4 95.1 113 3.77 NA NA 1 1 5 2
Ford Pantera L 15.8 8 351.0 264 4.22 3.170 14.50 0 1 5 4
Ferrari Dino 19.7 6 145.0 175 3.62 NA NA 0 1 5 6
Maserati Bora 15.0 8 301.0 335 3.54 3.570 14.60 0 1 5 8
Volvo 142E 21.4 4 121.0 109 4.11 NA NA 1 1 4 2
2) Base R With base R we can use within like this giving the same result.
within(mtcars, {
drat <- ifelse(drat <= 3, NA, drat)
wt <- ifelse(wt <= 3, NA, wt)
qsec <- ifelse(is.na(drat) | is.na(wt), NA, qsec)
})
or at the expense of some redundancy we could use transform:
transform(mtcars,
drat = ifelse(drat <= 3, NA, drat),
wt = ifelse(wt <= 3, NA, wt),
qsec = ifelse(drat <= 3 | wt <= 3, NA, qsec))
CodePudding user response：
Since the question is not tagged tidyverse here is a base R way with is.na<-.
is.na(mtcars$drat) <- mtcars$drat < 3
is.na(mtcars$wt) <- mtcars$wt < 3
is.na(mtcars$qsec) <- with(mtcars, is.na(drat) | is.na(wt))