How to delete and then create all variable names in a data.frame in R?

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Let’s say I have a data.frame 6x5, for example:

print(Dados)

Linha  A   B   C   D   E
L1     4   3   2   2   4
L2     1   11  1   1   1
L3     0   1   2   3   4
L4     2   0   0   8   0

But I want to exclude the "head" of data.frame, i.e., exclude the names of all variables, example:

print(Dados_Sem_Cabeça)

    L1     4   3   2   2   4
    L2     1   11  1   1   1
    L3     0   1   2   3   4
    L4     2   0   0   8   0

And then I would like to create a "new head" with different variable names, example:

print(Dados_Cabeça_Nova)

    C1   C2   C3   C4   C5  C6
    L1   4    3    2    2   4
    L2   1    11   1    1   1
    L3   0    1    2    3   4
    L4   2    0    0    8   0

NOTE: I cannot select the names of the variables because when the data.frame undergo updates the names of the variables will change, example:

print(Dados_Atualizados)

    Linha  B   C   D   E   F
    L1     4   3   2   2   4
    L2     1   11  1   1   1
    L3     0   1   2   3   4
    L4     2   0   0   8   0

How can I delete and then create all variable names in one data.frame?

r

2 answers

2

You’ll have to pass NULL to the names of your data.frame

"Excluding":

names(iris)
[1] "Sepal.Length" "Sepal.Width"  "Petal.Length" "Petal.Width"  "Species"     
names(iris) <- NULL
names(iris)
NULL
head(iris, 2)

1 5.1 3.5 1.4 0.2 setosa
2 4.9 3.0 1.4 0.2 setosa

Renaming:

names(iris) <- paste0("Nome", 1:5)
names(iris)
[1] "Nome1" "Nome2" "Nome3" "Nome4" "Nome5"
head(iris,2)
  Nome1 Nome2 Nome3 Nome4  Nome5
1   5.1   3.5   1.4   0.2 setosa
2   4.9   3.0   1.4   0.2 setosa

  • Thank you for the reply @Guilherme Parreira. But in my case I can’t use variable names because with each update of the data.frame they change. I edited the question by adding this little detail.

  • 1

    pq vc need to delete the actual names?

  • Pq I cannot select for example the variable "A", pq in the next update the variable changes. Example: Variáveis_Hoje = A, B, C, D, E and then changes to Variáveis_Amanhã: B,C,D,E,F. If I select by name "A" in the next update my script will give error, pq the variable "A" will no longer exist.

  • The idea of deleting the "head" of the data.frame is to make sure that my script does not depend on the names of the variables that always change.

  • 1

    um, got it, so it’s using the NULL same. because then you can’t call the column name directly.

  • How can I use the NULL? And how to add the line with other variable names? You can edit your answer by clarifying please?

  • but I edited my answer with the NULL

  • Let’s go continue this discussion in chat.

Show 3 more comments

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Actually the solution is quite simple: you do not need to delete the names. Every time you update the data.frame just update also what are the columns.

EXAMPLE

I will create an example data.frame from an array

dados = as.data.frame(matrix(sample(x=1:10, size = 20, replace = T), nrow=4))

which may result in 

   V1 V2 V3 V4 V5
1  5  6  1  2  6
2  9  6  9  4 10
3  1  9  1  6  5
4 10  6  9  8  6

Here you can update the names simply with the colnames()

colnames(dados) <- c('A', 'B', 'C', 'D', 'E')

and ready, your data.frame is now

   A B C D  E
1  5 6 1 2  6
2  9 6 9 4 10
3  1 9 1 6  5
4 10 6 9 8  6

OBSERVING

It’s my instinct based on the question you asked: I believe that because you’re in need of rewriting this data.frame probably you are addressing your problem in some way not optimized.

  • Thank you for the reply Flavio Barros. I reached the same conclusion of your reply tbm.

  • Even I was going to answer my own question with an answer close to yours, but you came first. Great solution!

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