purrr Questions
8
Solved
I often find questions where people have somehow ended up with an unnamed list of unnamed character vectors and they want to bind them row-wise into a data.frame. Here is an example:
library(magri...
Radman asked 5/5, 2020 at 13:58
7
Solved
Using reduce(bind_cols), the list elements of same dimension may be combined. However, I would like to know how to combine only same dimension (may be specified dimesion in some way) elements from ...
1
Solved
I want to run some modelling on each group of variables a and b. The problem is that nest() doesn't include the grouping variables which are needed by the model.
expand.grid(a = LETTERS[1:3], b = L...
2
Solved
I searched for ??"~" but this only points me to rlang::env_bind (presumably, %<~%) and base::~. Within RStudio, how can I find Purrr's ~'s documentation? For example, if I forgot how t...
4
Solved
I have multiple dataframes/tibbles with the same exact structure, but different contents. Their name is the only way I can differentiate them. The objective is to merge them all together into one d...
4
Solved
I have two data frames, one is survey data (data.csv) and another one is label data (label.csv). Here is the sample data (My original data has about 150 variables)
#sample data
df <- tibble::tr...
2
I am having problems with this ifelse sentence inside map function:
df<-list(mtcars,mtcars)
All I want to do is to organize each dataframe of this list this way:slice(x,c(n(),2:(n()-1),1))
map(...
Moldboard asked 28/4, 2021 at 23:21
5
Solved
This is a question for which I've written failsafes in my code before, but I'm wondering if there's something more straightforward that I've missed.
I sometimes have 2 (or more) lists that contai...
1
Solved
May be this question termed as part-3 of this question.
I know that arguments in lambda functions when used in tidyverse especially purrr functions are written as -
. when there is only 1 argument...
2
Solved
I have been exploring the various application of using pmap function and its variations recently and I am particularly interested in using c(...) to pass all the arguments into. The following data ...
1
Solved
I have this data frame and I would like to solely use pmap function to filter only rows where all values are either negative or positive. I am looking for a concise way of doing this as I thought a...
2
Solved
In base R I would do the following:
d <- data.frame(a = 1:4, b = 4:1, c = 2:5)
apply(d, 1, which.max)
With dplyr I could do the following:
library(dplyr)
d %>% mutate(u = purrr::pmap_int(lis...
5
3
Solved
Please help me
1) Why does map_if not work within a list
2) Is there a way to make it work
3) If not, what are the alternatives
Thanks in advance.
library(dplyr)
library(purrr)
cyl <- spli...
Asbury asked 14/3, 2017 at 9:35
2
Solved
I am converting a nested list of a specific structure (required by an API) to JSON using toJSON() in jsonlite. However, I need the final JSON to not contain the outer square brackets (also required...
2
Solved
I read the manual for using accumulate saying that it is a 2-argument function. I don't understand the given example:
1:5 %>% accumulate(`+`)
#> [1] 1 3 6 10 15
If accumulate is a 2-argument...
Ammonal asked 7/2, 2021 at 4:20
1
Solved
A user defined function
CollageImage <- function(path, country, strain, assay,subgroup) {
img_out <- magick::image_read(path) %>%
magick::image_trim() %>%
magick::image_convert(form...
Ebon asked 1/2, 2021 at 18:48
1
Referring to the documentation for across() (https://dplyr.tidyverse.org/reference/across.html), you can specify the name returned from the dplyr verb using the .names argument. Viz
iris %>%
gr...
4
1
I am trying to replace the NULL elements of the list below with NAs inside a map() before using rbindlist on the cleaned list:
m = list(min = list(id = "min", val = NULL),
max = list(id = "max",...
Burrill asked 28/2, 2019 at 23:50
3
Solved
I want to know the best way to iterate over rows of a data frame when the value of a variable at row n depends on the value of variable(s) at row n-1 and/or n-2. Ideally I would like to do this in ...
3
Solved
My data consist of an identifier (srdr_id), and a list column.
dat <- structure(list(srdr_id = c("174136", "174258", "174684"), outcomes = list(
structure(list(outcome_s = c("use_alcohol", "us...
3
Solved
I am using the map function of the purrr package in R which gives as output a list. Now I would like the output to be a named list based on the input. An example is given below.
input <- c("a",...
4
Solved
This is my transaction data. It shows the transactions made from the accounts in from column to the accounts in to column with the date and the amount information
data
id from to date amount
<...
Parasang asked 8/9, 2020 at 13:51
4
Solved
What is the purrr::map equivalent of:
for (i in 1:4) {
for (j in 1:6) {
print(paste(i, j, sep = "-"))
}
}
OR
lapply(1:4, function(i)
lapply(1:6, function(j)
print(paste(i, j, sep = "-")...
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