df is a test dataframe and I need to sort the last three columns in ascending order (without hardcoding the order).
df <- data.frame(X = c(1, 2, 3, 4, 5),
Z = c(1, 2, 3, 4, 5),
Y = c(1, 2, 3, 4, 5),
A = c(1, 2, 3, 4, 5),
C = c(1, 2, 3, 4, 5),
B = c(1, 2, 3, 4, 5))
Desired output:
> df
X Z Y A B C
1 1 1 1 1 1 1
2 2 2 2 2 2 2
3 3 3 3 3 3 3
4 4 4 4 4 4 4
5 5 5 5 5 5 5
I'm aware of the order() function but I can't seem to find the right way to implement it to get the desired output.
Update:
Base R:
cbind(df[1:3],df[4:6][,order(colnames(df[4:6]))])
First answer:
We could use relocate from dplyr:
https://dplyr.tidyverse.org/reference/relocate.html
It is configured to arrange columns:
Here we relocate by the index.
We take last (index = 6) and put it before (position 5, which is C)
library(dplyr)
df %>%
relocate(6, .before = 5)
An alternative:
library(dplyr)
df %>%
select(order(colnames(df))) %>%
relocate(4:6, .before = 1)
X Z Y A B C
1 1 1 1 1 1 1
2 2 2 2 2 2 2
3 3 3 3 3 3 3
4 4 4 4 4 4 4
5 5 5 5 5 5 5
In base R, a selection on the first columns then sort the last 3 names :
df[, c(names(df)[1:(ncol(df)-3)], sort(names(df)[ncol(df)-2:0]))]
We want to reorder the columns based on the column names, so if we use names(df) as the argument to order, we can reorder the data frame as follows.
The complicating factor is that order() returns a vector of numbers, so if we want to reorder only a subset of the column names, we'll need an approach that retains the original sort order for the first three columns.
We accomplish this by creating a vector of the first 3 column names, the sorted remaining column names using a function that returns the values rather than locations in the vector, and then use this with the [ form of the extract operator.
df <- data.frame(X = c(1, 2, 3, 4, 5),
Z = c(1, 2, 3, 4, 5),
Y = c(1, 2, 3, 4, 5),
A = c(1, 2, 3, 4, 5),
C = c(1, 2, 3, 4, 5),
B = c(1, 2, 3, 4, 5))
df[,c(names(df[1:3]),sort(names(df[4:6])))]
...and the output:
> df[,c(names(df[1:3]),sort(names(df[4:6])))]
X Z Y A B C
1 1 1 1 1 1 1
2 2 2 2 2 2 2
3 3 3 3 3 3 3
4 4 4 4 4 4 4
5 5 5 5 5 5 5
to_order <- seq(ncol(df)) > ncol(df) - 3
df[order(to_order*order(names(df)))]
#> X Z Y A B C
#> 1 1 1 1 1 1 1
#> 2 2 2 2 2 2 2
#> 3 3 3 3 3 3 3
#> 4 4 4 4 4 4 4
#> 5 5 5 5 5 5 5
Created on 2021-12-24 by the reprex package (v2.0.1)
Related
I have a large list with thousands of data frames included in it. These data frames have multiple columns each. Thereby, I want to automatically bind in each of these data frames the columns into one column. This means that they are appended below each other as shown below. Thereafter, I would transform the list to a data frame which would have varying column lengths due to the different number of columns within each element in the original list.
From this:
y1 y2
1 4
2 5
3 6
To this:
y1
1
2
3
4
5
6
This should be done for each element in the list, whereby the solution needs to take into account that there are thousands of different data frames, which cannot be mentioned individually (example):
df1 = data.frame(
X1 = c(1, 2, 3),
X1.2 = c(4, 5, 6)
)
df2 = data.frame(
X2 = c(7, 8, 9),
X2.2 = c(1, 4, 6)
)
df3 = data.frame(
X3 = c(3, 4, 1),
X3.2 = c(8, 3, 5),
X3.3 = c(3, 1, 9)
)
listOfDataframe = list(df1, df2, df3)
Final output:
df_final = data.frame(
X1 = c(1, 2, 3, 4, 5, 6),
X2 = c(7, 8, 9, 1, 4, 6),
X3 = c(3, 4, 1, 8, 3, 5, 3, 1, 9)
)
Another problem underlying this question is that there will be a differing number of rows, which I do not know how to account for in the data frame, as the columns need to have the same length.
Thank you in advance for your help, it is highly appreciated.
Structure of list within R:
We can unlist after looping over the list with lapply
lst1 <- lapply(listOfDataframe, \(x)
setNames(data.frame(unlist(x, use.names = FALSE)), names(x)[1]))
-output
lst1
[[1]]
X1
1 1
2 2
3 3
4 4
5 5
6 6
[[2]]
X2
1 7
2 8
3 9
4 1
5 4
6 6
[[3]]
X3
1 3
2 4
3 1
4 8
5 3
6 5
7 3
8 1
9 9
If we need to convert the list to a single data.frame, use cbind.na from qPCR
do.call(qpcR:::cbind.na, lst1)
X1 X2 X3
1 1 7 3
2 2 8 4
3 3 9 1
4 4 1 8
5 5 4 3
6 6 6 5
7 NA NA 3
8 NA NA 1
9 NA NA 9
Here is a tidyverse solution:
library(dplyr)
library(purrr)
listOfDataframe %>%
map(~.x %>% stack(.)) %>%
map(~.x %>% select(-ind))
[[1]]
values
1 1
2 2
3 3
4 4
5 5
6 6
[[2]]
values
1 7
2 8
3 9
4 1
5 4
6 6
[[3]]
values
1 3
2 4
3 1
4 8
5 3
6 5
7 3
8 1
9 9
I have a dataframe with observations from three years time, with column df$week that indicates the week of the observation. (The week count of the second year continues from the count of the first, so the data contains 207 weeks).
I would like to divide the data to longer time periods, to df$period that would include all observations from several weeks' time.
If a period would be the length of three weeks, and I the data would include 13 observations in six weeks time, the I idea would be to divide
weeks <- c(1, 1, 1, 2, 2, 3, 3, 4, 5, 5, 6, 6, 6)
into
periods <- c(1, 1, 1, 2, 2, 3, 3), c(4, 5, 5, 6, 6, 6)
periods
[1]
1 1 1 2 2 3 3
[2]
4 5 5 6 6 6
To look something like
> df
week period
1 1 1
2 1 1
3 1 1
4 2 1
5 2 1
6 3 1
7 3 1
8 4 2
9 5 2
10 5 2
11 6 2
12 6 2
13 6 2
>
The data contains +13k rows so would need to do some sort of map in style of
mapPeriod <- function(df, fun) {
out <- vector("vector_of_weeks", length(df))
for (i in seq_along(df)) {
out[i] <- fun(df[[i]])
}
out
}
I just don't know what to include in the fun to divide the weeks to the decided sequences of periods. Can function rep be of assistance here? How?
I would be very grateful for all input and suggestions.
split(weeks, f = (weeks - 1) %/% 3)
$`0`
[1] 1 1 1 2 2 3 3
$`1`
[1] 4 5 5 6 6 6
from comments below
weeks <- c(1, 1, 1, 2, 2, 3, 3, 4, 5, 5, 6, 6, 6)
df <- data.frame(weeks)
library(data.table)
df$period <- data.table::rleid((weeks - 1) %/% 3)
# weeks period
# 1 1 1
# 2 1 1
# 3 1 1
# 4 2 1
# 5 2 1
# 6 3 1
# 7 3 1
# 8 4 2
# 9 5 2
# 10 5 2
# 11 6 2
# 12 6 2
# 13 6 2
I have 2 vectors:
v1 <- c(1, 2, 3, 4, 1, 3, 5, 6, 4)
v2 <- c(1, 2, 3, 4, 5, 6, 7)
I want to calculate the occurrence of values of v1 in v2. The expected result is:
1 2 3 4 5 6 7
2 1 2 2 1 1 0
I know there is a function can do this:
table(v1[v1 %in% v2])
However, it only list the matched values:
1 2 3 4 5 6
2 1 2 2 1 1
How can I show all the values in v2?
You can do
table(factor(v1, levels=unique(v2)))
# 1 2 3 4 5 6 7
# 2 1 2 2 1 1 0
Extending this former question, how can I shuffle (randomize) the following vector
a1 = c(1, 1, 2, 2, 2, 2, 3, 3, 4, 5, 5, 5)
in order to get something like this:
a2 = c(5, 5, 3, 3, 3, 3, 1, 1, 2, 4, 4, 4)
or even better like this:
a3 = c(4, 4, 4, 2, 3, 3, 3, 3, 1, 1, 5, 5)?
such that each element could randomly change to another but with keeping the number of each element constant?
You can try something like this: create a factor from a1 with randomly shuffled levels and then convert it to integers:
as.integer(factor(a1, levels = sample(unique(a1), length(unique(a1)))))
# [1] 5 5 4 4 4 4 3 3 2 1 1 1
The data:
a1 <- c(1, 1, 2, 2, 2, 2, 3, 3, 4, 5, 5, 5)
First steps:
# extract values and their frequencies
val <- unique(a1)
tab <- table(a1)
freq <- tab[as.character(val)]
Keep original order of frequencies but sample values
rep(sample(val), freq)
# [1] 4 4 1 1 1 1 3 3 5 2 2 2
Keep original frequencies but sample order of values
rep(sa <- sample(val), freq[as.character(sa)])
# [1] 4 2 2 2 2 3 3 1 1 5 5 5
Seems like a perfect application for rle and its inverse rep:
rand_inverse_rle <- function(x) { x=sort(x)
ord=sample (length(rle(x)$values) )
unlist( mapply( rep, rle(x)$values[ord], rle(x)$lengths[ord]))}
rand_inverse_rle(a1)
#----------
[1] 3 3 4 5 5 5 2 2 2 2 1 1
This was my reading of a function needed to satisfy the natural language requirements:
> a1 = sample( c(1, 1, 2, 2, 2, 2, 3, 3, 4, 5, 5, 5) )
> a1
[1] 5 2 5 2 5 1 3 4 2 2 3 1
> rand_inverse_rle(a1)
[1] 5 5 5 4 2 2 2 2 3 3 1 1
> rand_inverse_rle(a1)
[1] 1 1 3 3 5 5 5 2 2 2 2 4
> rand_inverse_rle(a1)
[1] 1 1 3 3 4 5 5 5 2 2 2 2
I am generating dataframes with different amounts of variables, which are in the wrong positions most of the time.
e.g. this dataframe
df <- structure(list(A = c(1, 2, 3, 4, 5), F = c(5, 4, 3, 2, 1), D = c(5,
5, 4, 4, 1)), .Names = c("A", "F", "D"), row.names = c(NA, 5L
), class = "data.frame")
A F D
1 1 5 5
2 2 4 5
3 3 3 4
4 4 2 4
5 5 1 1
I have a vector that helps me knowing what the right order should be, e.g.:
c("A","B","C","D","E","F")
How can I use this vector put, programmatically my generated dataframes in the right order?
According to the vector, this should be the result:
A D F
1 1 5 5
2 2 5 4
3 3 4 3
4 4 4 2
5 5 1 1
Any ideas? most welcome!
intersect should work for this:
df[intersect(colorder, names(df))]
# A D F
# 1 1 5 5
# 2 2 5 4
# 3 3 4 3
# 4 4 4 2
# 5 5 1 1