Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Should data_frame() forbid POSIXlt? #813

Closed
hadley opened this issue Nov 26, 2014 · 3 comments
Closed

Should data_frame() forbid POSIXlt? #813

hadley opened this issue Nov 26, 2014 · 3 comments
Labels
feature a feature request or enhancement
Milestone

Comments

@hadley
Copy link
Member

hadley commented Nov 26, 2014

or in general, any list with a class? Unless it's been specifically designed to work as a list column, it will only have the right number of elements by chance:

mod <- lm(mpg ~ wt, data = mtcars)
data_frame(x = 1:12, y = mod)

data_frame(x = 1:11, y = as.POSIXlt(Sys.time()))
@romainfrancois
Copy link
Member

What about coercing POSIXlt to POSIXct with a warning ?

@hadley
Copy link
Member Author

hadley commented Nov 26, 2014

What should we do for the linear model case? I'd rather be consistent, and I think is.list(x) && !is.vector(x) is probably a good test for an object that's unlikely to behave correctly.

@hadley hadley added the feature a feature request or enhancement label Dec 2, 2014
@hadley hadley added this to the 0.4 milestone Dec 2, 2014
@hadley hadley changed the title Should data_frames forbid POSIXlt? Should data_frame() forbid POSIXlt? Oct 22, 2015
@hadley hadley closed this as completed in 142145e Oct 28, 2015
krlmlr pushed a commit to krlmlr/dplyr that referenced this issue Mar 2, 2016
krlmlr pushed a commit to tidyverse/tibble that referenced this issue Mar 22, 2016
- Initial CRAN release

- Extracted from `dplyr` 0.4.3

- Exported functions:
    - `tbl_df()`
    - `as_data_frame()`
    - `data_frame()`, `data_frame_()`
    - `frame_data()`, `tibble()`
    - `glimpse()`
    - `trunc_mat()`, `knit_print.trunc_mat()`
    - `type_sum()`
    - New `lst()` and `lst_()` create lists in the same way that
      `data_frame()` and `data_frame_()` create data frames (tidyverse/dplyr#1290).
      `lst(NULL)` doesn't raise an error (#17, @jennybc), but always
      uses deparsed expression as name (even for `NULL`).
    - New `add_row()` makes it easy to add a new row to data frame
      (tidyverse/dplyr#1021).
    - New `rownames_to_column()` and `column_to_rownames()` (#11, @zhilongjia).
    - New `has_rownames()` and `remove_rownames()` (#44).
    - New `repair_names()` fixes missing and duplicate names (#10, #15,
      @r2evans).
    - New `is_vector_s3()`.

- Features
    - New `as_data_frame.table()` with argument `n` to control name of count
      column (#22, #23).
    - Use `tibble` prefix for options (#13, #36).
    - `glimpse()` now (invisibly) returns its argument (tidyverse/dplyr#1570). It
      is now a generic, the default method dispatches to `str()`
      (tidyverse/dplyr#1325).  The default width is obtained from the
      `tibble.width` option (#35, #56).
    - `as_data_frame()` is now an S3 generic with methods for lists (the old
      `as_data_frame()`), data frames (trivial), matrices (with efficient
      C++ implementation) (tidyverse/dplyr#876), and `NULL` (returns a 0-row
      0-column data frame) (#17, @jennybc).
    - Non-scalar input to `frame_data()` and `tibble()` (including lists)
      creates list-valued columns (#7). These functions return 0-row but n-col
      data frame if no data.

- Bug fixes
    - `frame_data()` properly constructs rectangular tables (tidyverse/dplyr#1377,
      @kevinushey).

- Minor modifications
    - Uses `setOldClass(c("tbl_df", "tbl", "data.frame"))` to help with S4
      (tidyverse/dplyr#969).
    - `tbl_df()` automatically generates column names (tidyverse/dplyr#1606).
    - `tbl_df`s gain `$` and `[[` methods that are ~5x faster than the defaults,
      never do partial matching (tidyverse/dplyr#1504), and throw an error if the
      variable does not exist.  `[[.tbl_df()` falls back to regular subsetting
      when used with anything other than a single string (#29).
      `base::getElement()` now works with tibbles (#9).
    - `all_equal()` allows to compare data frames ignoring row and column order,
      and optionally ignoring minor differences in type (e.g. int vs. double)
      (tidyverse/dplyr#821).  Used by `all.equal()` for tibbles.  (This package
      contains a pure R implementation of `all_equal()`, the `dplyr` code has
      identical behavior but is written in C++ and thus faster.)
    - The internals of `data_frame()` and `as_data_frame()` have been aligned,
      so `as_data_frame()` will now automatically recycle length-1 vectors.
      Both functions give more informative error messages if you are attempting
      to create an invalid data frame.  You can no longer create a data frame
      with duplicated names (tidyverse/dplyr#820).  Both functions now check that
      you don't have any `POSIXlt` columns, and tell you to use `POSIXct` if you
      do (tidyverse/dplyr#813).  `data_frame(NULL)` raises error "must be a 1d
      atomic vector or list".
    - `trunc_mat()` and `print.tbl_df()` are considerably faster if you have
      very wide data frames.  They will now also only list the first 100
      additional variables not already on screen - control this with the new
      `n_extra` parameter to `print()` (tidyverse/dplyr#1161).  The type of list
      columns is printed correctly (tidyverse/dplyr#1379).  The `width` argument is
      used also for 0-row or 0-column data frames (#18).
    - When used in list-columns, S4 objects only print the class name rather
      than the full class hierarchy (#33).
    - Add test that `[.tbl_df()` does not change class (#41, @jennybc).  Improve
      `[.tbl_df()` error message.

- Documentation
    - Update README, with edits (#52, @bhive01) and enhancements (#54,
      @jennybc).
    - `vignette("tibble")` describes the difference between tbl_dfs and
      regular data frames (tidyverse/dplyr#1468).

- Code quality
    - Test using new-style Travis-CI and AppVeyor. Full test coverage (#24,
      #53). Regression tests load known output from file (#49).
    - Renamed `obj_type()` to `obj_sum()`, improvements, better integration with
     `type_sum()`.
    - Internal cleanup.
@ghost
Copy link

ghost commented Aug 15, 2016

I don't think I like this decision. I agree that POSIXct is the target structure, but, when you get POSIXlt data from another package (e.g., weatherData::getSummarizedData), it's nice to be able to convert it with mutate (i.e., inside the dplyr environment), rather than having to flip back to older ways. It's just a simple dataframe %>% mutate(Date = as.POSIXct(Date)), and dataframe is just a data frame, not a tbl_df (or tibble, I guess now).

@lock lock bot locked as resolved and limited conversation to collaborators Jun 8, 2018
Sign up for free to subscribe to this conversation on GitHub. Already have an account? Sign in.
Labels
feature a feature request or enhancement
Projects
None yet
Development

No branches or pull requests

2 participants