例如, 如果我运行以下代码:
mtcars$cyl[2:5] = 'a'
mtcars %>%
arrow_table() %>%
mutate(cyl = cast(cyl, numeric())) %>%
collect()
弹出错误消息:
Error in `compute.arrow_dplyr_query()`:
! Invalid: Failed to parse string: 'a' as a scalar of type double
Run `rlang::last_trace()` to see where the error occurred.
我希望结果不会有错误,并且那些“a”将被转换为
NA
。然而,cast
函数的性质似乎与r中的as.numeric
不一样。
试试这个:
mtcars %>%
mutate(cyl = as.numeric(cyl))
mpg cyl disp hp drat wt qsec vs am gear carb
Mazda RX4 21.0 6 160.0 110 3.90 2.620 16.46 0 1 4 4
Mazda RX4 Wag 21.0 NA 160.0 110 3.90 2.875 17.02 0 1 4 4
Datsun 710 22.8 NA 108.0 93 3.85 2.320 18.61 1 1 4 1
Hornet 4 Drive 21.4 NA 258.0 110 3.08 3.215 19.44 1 0 3 1
Hornet Sportabout 18.7 NA 360.0 175 3.15 3.440 17.02 0 0 3 2
Valiant 18.1 6 225.0 105 2.76 3.460 20.22 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