Input error with sapply of anonymous function #155
Description
I have been running into issues when using dtplyr on mutating columns with custom functions, sometimes named and sometimes anonymous. The error I get is usually a non-descriptive Error: Invalid input . I've created one toy example where I get this error using an anonymous function but simply naming the function makes the error go away. I'm not sure that whether the error is necessarily related to anonymous functions because I
- have gotten this error when calling
sapply()on customed, named functions - don't always get this error when calling
sapply()on anonymous functions
Any thoughts?
library(data.table)
library(dplyr)
library(dtplyr)
set.seed(100)
df <- data.frame("x" = rnorm(100),
"y" = rnorm(100))
dt <- lazy_dt(df)
### This doesn't work for dt
df %>%
mutate("filtered_mean" = sapply(x, function(x, y) {mean(y[y <= abs(x)])}, y)) %>%
head()
x y filtered_mean
1 -0.50219235 -0.3329234 -0.3115360
2 0.13153117 1.3631137 -0.5083479
3 -0.07891709 -0.4691473 -0.5310105
4 0.88678481 0.8428756 -0.1957230
5 0.11697127 -1.4579937 -0.5310105
6 0.31863009 -0.4003059 -0.3851345
dt %>%
mutate("filtered_mean" = sapply(x, function(x, y) {mean(y[y <= abs(x)])}, y)) %>%
as_tibble() %>%
head()
Error: Invalid input
### But this works for dt
my_function <- function(x, y) {
return(mean(y[y <= abs(x)]))
}
df %>%
mutate("filtered_mean" = sapply(x, my_function, y)) %>%
head()
x y filtered_mean
1 -0.50219235 -0.3329234 -0.3115360
2 0.13153117 1.3631137 -0.5083479
3 -0.07891709 -0.4691473 -0.5310105
4 0.88678481 0.8428756 -0.1957230
5 0.11697127 -1.4579937 -0.5310105
6 0.31863009 -0.4003059 -0.3851345
dt %>%
mutate("filtered_mean" = sapply(x, my_function, y)) %>%
as_tibble() %>%
head()
# A tibble: 6 x 3
x y filtered_mean
<dbl> <dbl> <dbl>
1 -0.502 -0.333 -0.312
2 0.132 1.36 -0.508
3 -0.0789 -0.469 -0.531
4 0.887 0.843 -0.196
5 0.117 -1.46 -0.531
6 0.319 -0.400 -0.385