[R] graphics useRaster check_irregular definition for date or posix
cd@@ek m@iii@g oii posteo@de
cd@@ek m@iii@g oii posteo@de
Tue Apr 13 17:11:39 CEST 2021
Hi
The function `check_irregular()` defined within
`graphics::image.default()` checks if the `useRaster` argument for
`graphics::image()` can be true or must be false.
According to this function, the following example vector is irregular:
```
time <- seq(as.Date("2020-1-1"), as.Date("2020-12-31"), l=12)
check_irregular(time, time)
# TRUE
```
In my view, this is not correct.
In this case, the `all.equal`-call does not evaluate to true due to the
special class of `dx` (or `dy`). If I slightly rewrite the function as
```
my_check_irregular <- function (x, y)
{
dx <- as.numeric(diff(x))
dy <- as.numeric(diff(y))
(length(dx) && !isTRUE(all.equal(dx, rep(dx[1], length(dx))))) ||
(length(dy) && !isTRUE(all.equal(dy, rep(dy[1], length(dy)))))
}
```
the correct answer is obtained (i.e. that the input vector is not
irregular based on the rational behind `all.equal`):
```
my_check_irregular(time, time)
# FALSE
```
The same applies to POSIX* objects. I was wondering if this is intended
or not?
Thanks a lot for any answer,
Chris
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