How to include a value in the last line of a data.frame in R

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1

I have a date.frame and a value in R, I needed this value to be included in the last row of a certain column of this date.frame. I’ve tested the function rbind but it didn’t work.

x <- c(1:15)
y <- c(1:15)
z <- 4
df <- data.frame(x,y)
df <- rbind(x, z)
r

  • The question is not well formulated. What is the expected answer to it, since df has two columns and z has only one observation? The last line should be formed by c(4, 4)? Or c(NA, 4)? Or else c(4, NA)? Please check this and be more clear about your needs.

  • Forgiveness, the value of Z should be included in the last line of X, therefore c(4, NA)

  • But x has only one dimension. By chance c(4, NA) should be the last line of df?

  • Yes, df should have 16 lines, and the last should be c(4, NA)

2 answers

2


Create the data frame z with the desired observations, making sure that the names of their columns match the names of the columns of df:

x <- c(1:15)
y <- c(1:15)
df <- data.frame(x,y)
names(df)
# [1] "x" "y"

z <- data.frame(x = 4, y = NA)
df <- rbind(df, z)
df
#     x  y
# 1   1  1
# 2   2  2
# 3   3  3
# 4   4  4
# 5   5  5
# 6   6  6
# 7   7  7
# 8   8  8
# 9   9  9
# 10 10 10
# 11 11 11
# 12 12 12
# 13 13 13
# 14 14 14
# 15 15 15
# 16  4 NA

0

You can add values at any positions directly, it is not necessary to create an object just for that:

df <- data.frame(x = 1:15,
                 y = 1:15)

df[nrow(df)+1, "x"] <- 4

> tail(df)
    x  y
11 11 11
12 12 12
13 13 13
14 14 14
15 15 15
16  4 NA

If the position already exists, the value is replaced. If not, the data.frame is resized and Nas inserted by default.

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