[R] Convert R object to a data frame
Rui Barradas
ru|pb@rr@d@@ @end|ng |rom @@po@pt
Thu Jun 4 23:19:09 CEST 2026
Às 21:57 de 04/06/2026, Sorkin, John escreveu:
> I have an R object created lapply function within a by a by function
>
> results_by_date <- by(
> data,
> data[,"Date"],
> function(subdata) {
> lapply(
> alertlevels,
> check_cutpoints2,
> data=subdata,
> mycolumn=column
> )
> }
> )
>
> which has the following structure
>
> $ 2020-08-14:List of 4
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.1
> .. ..$ NumPeopleExposed: int 0
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.2
> .. ..$ NumPeopleExposed: int 0
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.3
> .. ..$ NumPeopleExposed: int 0
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.4
> .. ..$ NumPeopleExposed: int 0
> $ 2020-08-15:List of 4
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.1
> .. ..$ NumPeopleExposed: int 1
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.2
> .. ..$ NumPeopleExposed: int 0
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.3
> .. ..$ NumPeopleExposed: int 0
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.4
> .. ..$ NumPeopleExposed: int 0
> $ 2020-08-16:List of 4
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.1
> .. ..$ NumPeopleExposed: int 15
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.2
> .. ..$ NumPeopleExposed: int 6
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.3
> .. ..$ NumPeopleExposed: int 6
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.4
> .. ..$ NumPeopleExposed: int 6
> $ 2020-08-17:List of 4
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.1
> .. ..$ NumPeopleExposed: int 58
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.2
> .. ..$ NumPeopleExposed: int 20
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.3
> .. ..$ NumPeopleExposed: int 7
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.4
> .. ..$ NumPeopleExposed: int 2
> $ 2020-08-18:List of 4
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.1
> .. ..$ NumPeopleExposed: int 79
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.2
> .. ..$ NumPeopleExposed: int 45
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.3
> .. ..$ NumPeopleExposed: int 16
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.4
> .. ..$ NumPeopleExposed: int 6
> $ 2020-08-19:List of 4
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.1
> .. ..$ NumPeopleExposed: int 187
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.2
> .. ..$ NumPeopleExposed: int 100
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.3
> .. ..$ NumPeopleExposed: int 61
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.4
> .. ..$ NumPeopleExposed: int 38
> $ 2020-08-20:List of 4
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.1
> .. ..$ NumPeopleExposed: int 121
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.2
> .. ..$ NumPeopleExposed: int 31
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.3
> .. ..$ NumPeopleExposed: int 13
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.4
> .. ..$ NumPeopleExposed: int 4
> $ 2020-08-21:List of 4
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.1
> .. ..$ NumPeopleExposed: int 17
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.2
> .. ..$ NumPeopleExposed: int 8
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.3
> .. ..$ NumPeopleExposed: int 5
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.4
> .. ..$ NumPeopleExposed: int 3
> $ 2020-08-22:List of 4
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.1
> .. ..$ NumPeopleExposed: int 35
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.2
> .. ..$ NumPeopleExposed: int 12
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.3
> .. ..$ NumPeopleExposed: int 6
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.4
> .. ..$ NumPeopleExposed: int 2
> $ 2020-08-23:List of 4
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.1
> .. ..$ NumPeopleExposed: int 32
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.2
> .. ..$ NumPeopleExposed: int 15
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.3
> .. ..$ NumPeopleExposed: int 8
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.4
> .. ..$ NumPeopleExposed: int 4
> $ 2020-08-24:List of 4
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.1
> .. ..$ NumPeopleExposed: int 15
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.2
> .. ..$ NumPeopleExposed: int 5
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.3
> .. ..$ NumPeopleExposed: int 1
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.4
> .. ..$ NumPeopleExposed: int 0
> $ 2020-08-25:List of 4
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.1
> .. ..$ NumPeopleExposed: int 43
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.2
> .. ..$ NumPeopleExposed: int 26
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.3
> .. ..$ NumPeopleExposed: int 13
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.4
> .. ..$ NumPeopleExposed: int 5
> $ 2020-08-26:List of 4
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.1
> .. ..$ NumPeopleExposed: int 0
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.2
> .. ..$ NumPeopleExposed: int 0
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.3
> .. ..$ NumPeopleExposed: int 0
> ..$ :List of 2
> .. ..$ criticalvalue : num 0.4
> .. ..$ NumPeopleExposed: int 0
> - attr(*, "dim")= int 13
> - attr(*, "dimnames")=List of 1
> ..$ data[, "Date"]: chr [1:13] "2020-08-14" "2020-08-15" "2020-08-16" "2020-08-17" ...
> - attr(*, "call")= language by.data.frame(data = data, INDICES = data[, "Date"], FUN = function(subdata) { lapply(alertlevels, check_cutp| __truncated__ ...
> - attr(*, "class")= chr "by"
> NULL
>
> I would like to convert the object to a dataframe. Can anyone suggest how I might accomplish this task?
>
> Thank you,
> John
>
> John David Sorkin M.D., Ph.D.
> Professor of Medicine, University of Maryland School of Medicine;
> Associate Director for Biostatistics and Informatics, Baltimore VA Medical Center Geriatrics Research, Education, and Clinical Center;
> Former PI Biostatistics and Informatics Core, University of Maryland School of Medicine Claude D. Pepper Older Americans Independence Center;
> Senior Statistician University of Maryland Center for Vascular Research;
>
> Division of Gerontology, Geriatrics and Palliative Medicine,
> 10 North Greene Street
> GRECC (BT/18/GR)
> Baltimore, MD 21201-1524
> Cell phone 443-418-5382
>
>
>
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Hello,
The problem is that you have a lapply() nested in by(), so you will have
to rbind twice.
It seems that
results_by_date <- by(
data,
data[,"Date"],
function(subdata) {
lapply(
alertlevels,
check_cutpoints2,
data=subdata,
mycolumn=column
) |> do.call(rbind, args = _)
}
) |> do.call(rbind, args = _)
can solve it.
Can you post the output of dput(results_by_date[1:2]) ?
Hope this helps,
Rui Barradas
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