CODEWITHSUNDEEP
rdataframe
Denis
Denis

Reputation: 12077

Why does 'rbind.data.frame' convert Date to numeric?

I am trying to understand why rbind.data.frame converts my dates to numeric format and how do I fix it. Suppose I have the following:

v <- list(
          row1=list(col1 = as.Date("2011-01-23"), col2="A"), 
          row2=list(col1 = as.Date("2012-03-03"), col2="B"))

Now I try to do:

df <- do.call(rbind.data.frame, v)
str(df)
'data.frame':   2 obs. of  2 variables:
 $ col1: num  14997 15402
 $ col2: Factor w/ 2 levels "A","B": 1 2

Why did col1 become a num? How do I fix it so it properly becomes a Date field in df.

NOTE: I would prefer a native R solution but other packages would be interesting to see

Upvotes: 5

Views: 1833

Answers (2)

user20650
user20650

Reputation: 25854

Building on 42-'s comment Rather than using list in the "inner" level of construction, use data.frame, for this example, you can convert the inner list to a data.frame, and then rbind works as expected.

> d = do.call(rbind, lapply(v, as.data.frame))
> str(d)
'data.frame':   2 obs. of  2 variables:
 $ col1: Date, format: "2011-01-23" "2012-03-03"
 $ col2: Factor w/ 2 levels "A","B": 1 2

Upvotes: 3

Sonny
Sonny

Reputation: 3183

Use dplyr

> library(dplyr)
> df <- bind_rows(v)
> df
# A tibble: 2 x 2
  col1       col2 
  <date>     <chr>
1 2011-01-23 A    
2 2012-03-03 B

Upvotes: 3

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