R: Dynamically Splitting A Data Frame

Question

I have a one column data frame. The length varies between 60,000 and 500,000 rows.

I would like to split the data frame into smaller data frames with 45,000 rows plus an additional data frame with any remaining rows. For example, if my starting data frame has 90,100 rows, the result should be 3 data frames - 2 with 45000 rows and 1 with 100 rows.

I would like to be able to subsequently process each of the resulting data frames in a for loop.

Is there a way to do this in R?

Answer 1

Another base R solution using split+%/%

r <- split(df,seq(nrow(df))%/%45000)

Answer 2

We can use split to create a list of data.frame by splitting on a grouping index created with gl

lst1 <- split(df1,  as.integer(gl(nrow(df1), 45000, nrow(df1))))
length(lst1)
#[1] 3
sapply(lst1, nrow)
#     1     2     3 
# 45000 45000   100 

data

set.seed(24)
df1 <- data.frame(col1 = rnorm(90100), col2 = runif(90100), id = 1:90100)