[R] About populating a dataframe in a loop

[Rui Barradas]

Hello,

Works with me:

set.seed(6574)

pre.mat = data.frame()
for(i in 1:10){
     mat.temp = data.frame(x = rnorm(5), A = sample(LETTERS, 5, TRUE))
     pre.mat = rbind(pre.mat, mat.temp)
}

nrow(pre.mat)  # should be 50


Can you give us an example that doesn't work?

Rui Barradas

Em 06-01-2017 18:00, lily li escreveu:
> Hi R users,
>
> I have a question about filling a dataframe in R using a for loop.
>
> I created an empty dataframe first and then filled it, using the code:
> pre.mat = data.frame()
> for(i in 1:10){
>      mat.temp = data.frame(some values filled in)
>      pre.mat = rbind(pre.mat, mat.temp)
> }
> However, the resulted dataframe has not all the rows that I desired for.
> What is the problem and how to solve it? Thanks.
>
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