i.e getting the count of each variable in each column with out having to do multiple group bus
This post:
group_by(across(all_of(vars, YEARS))) - grouping by variables with a fixed YEAR variable
seems to answer my question using this method purrr::map(vars, ~df %>% count(YEAR, .data[[.x]]))Is there a way to get the percentages at the same time as the counts?
I seem to get an error when I try to just add percent as the next step
I am struggling with a dataframe of exchange-rate observations taken 3 times a day for approximately 30 days. This means that currently the dataframe is formed by 90 observations. For the purpose of my research I need to reduce the observations to 1 per day (30 observations), possibly by making the mean every 3 observations. In sum, I need a code that takes the observations 3 by 3 and outputs one observation every 3. I have tried some different codes but my attempts have all completely failed. I was wondering if someone had to do something similar and managed.
Thanks!
Use group_by and summarise like this:
library(tidyverse)
df=tibble(
day = rep(1:30, each=3),
rate = rnorm(90)
)
df %>%
group_by(day) %>%
summarise(mrate = mean(rate))
P.S.
Attach data. It will be easier to help out on specific data.
I have a dataset with repeated measures: measurements nested within participants (ID) nested in groups. A variable G (with range 0-100) was measured on the group-level. I want to create a new column that shows:
The first day on which the maximum value of G was reached in a group coded as zero.
How many days each measurement (in this same group) occurred before or after the day on which the maximum was reached. For example: a measurement taken 2 days before the maximum is then coded -2, and a measurement 5 days after the maximum is coded as 5.
Here is an example of what I'm aiming for: Example
I highlighted the days on which the maximum value of G was reached in the different groups. The column 'New' is what I'm trying to get.
I've been trying with dplyr and I managed to get for each group the maximum with group_by, arrange(desc), slice. I then recoded those maxima into zero and joined this dataframe with my original dataframe. However, I cannot manage to do the 'sequence' of days leading up to/ days from the maximum.
EDIT: sorry I didn't include a reprex. I used this code so far:
To find the maximum value: First order by date
data <- data[with(data, order(G, Date)),]
Find maximum and join with original data:
data2 <- data %>%
dplyr::group_by(Group) %>%
arrange(desc(c(G)), .by_group=TRUE) %>%
slice(1) %>%
ungroup()
data2$New <- data2$G
data2 <- data2 %>%
dplyr::select(c("ID", "New", "Date"))
data3 <- full_join(data, data2, by=c("ID", "Date"))
data3$New[!is.na(data3$New)] <- 0
This gives me the maxima coded as zero and all the other measurements in column New as NA but not yet the number of days leading up to this, and the number of days since. I have no idea how to get to this.
It would help if you would be able to provide the data using dput() in your question, as opposed to using an image.
It looked like you wanted to group_by(Group) in your example to compute number of days before and after the maximum date in a Group. However, you have ID of 3 and Group of A that suggests otherwise, and maybe could be clarified.
Here is one approach using tidyverse I hope will be helpful. After grouping and arranging by Date, you can look at the difference in dates comparing to the Date where G is maximum (the first maximum detected in date order).
Also note, as.numeric is included to provide a number, as the result for New is a difftime (e.g., "7 days").
library(tidyverse)
data %>%
group_by(Group) %>%
arrange(Date) %>%
mutate(New = as.numeric(Date - Date[which.max(G)]))
I try to group by year and then calculate the average of means, but I don't know the fastest way to do it and the way I do it gives me an error.
First I calculate how many rows per year the table has:
avg_awarded_moves_year <- imdb_globes %>% group_by(year_film) %>%
tally()
And then again use transmute function to add the table the average per year.
avg_awarded_moves_year <- imdb_globes %>% group_by(year_film) %>%
transmute(average_per_year =
sum(averageRating)/avg_awarded_moves_year$n)
The error I encounter: Error: Column "average_per_year" must be length 12 (the group size) or one, not 76
I can bet that there is a faster and more eloquent way to do it. I tried to divide the sum by "n()" , but it didn't work as well. I don't want to use mean function because the sample consists o means already.
I have a large df with around 40.000.000 rows , covering in total a time period of 2 years and more than 400k unique users.
The time variable is formatted as POSIXct and I have a unique user_id per user. I observe each user over several points in time.
Each row is therefore a unqiue combination of user_id, time and a set of variables.
Based on a set of dummy variables (df$v1, df$v2), a category variable(df$category_var) and the time variable (df$time_var) I now want to calculate 3 new variables on a user_id level on a rolling time window over the previous 30 days.
So in each row, the new variable should be calculated over the values of the previous 30 days of the input variables.
I do not observe all users over the same time period, some enter later some leave earlier, also the distances between times are not equal, therefore I can not calculate the variables just by number of rows.
So far I only managed to calculate my new variables per user_id over the whole observation period, but I couldn’t achieve to calculate the variables for the previous 30 days rolling window per user.
After checking and trying all the related posts here, I assume a data.table solution is the most suitable, but since I have so far mainly worked with dplyr the attempt of calculating these variables on the rolling time window on a groupey_by user_id level has taken more than a week without any results. I would be so grateful for your support!
My df basically looks like :
user_id <- c(1,1,1,1,1,2,2,2,2,3,3,3,3,3)
time_var <- c(“,2,3,4,5, 1.5, 2, 3, 4.5, 1,2.5,3,4,5)
category_var <- c(“A”, “A”, “B”, “B”, “A”, “A”, “C”, “C”, “A”, …)
v1 <- c(0,1,0,0,1,0,1,1,1,0,1,…)
v2 <- c(1,1,0,1,0,1,1,0,...)
My first needed new variable (new_x1) is basically a cumulative sum based on a condition in dummy variable v1. What I achieved so far:
df <- df %>% group_by(user_id) %>% mutate(new_x1=cumsum(v1==1))
What I need: That variables only counting over the previoues 30 days per user
Needed new variable (new_x2): Basically cumulative count of v1 if v2 has a (so far) unique value. So for each new value in v2 given v1==1, count.
What I achieved so far:
df <- df %>%
group_by(user_id, category_var) %>%
mutate(new_x2 = cumsum(!duplicated(v2 )& v1==1))
I also need this based on the previous 30 days and not the whole observation period per user.
My third variable of interest (new__x3):
The time between two observations given a certain condition (v1==1)
#Interevent Time
df2 <- df%>% group_by(user_id) %>% filter(v1==1) %>% mutate(time_between_events=time-lag(time))
I would also need this on the previoues 30 days.
Thank you so much!
Edit after John Springs Post:
My potential solution would then be
setDT(df)[, `:=`(new_x1= cumsum(df$v1==1[df$user_id == user_id][between(df$time[df$user_id == user_id], time-30, time, incbounds = TRUE)]),
new_x2= cumsum(!duplicated(df$v1==1[df$user_id == user_id][between(df$time[df$user_id == user_id], time-30, time, incbounds = TRUE)]))),
by = eval(c("user_id", "time"))]
I really not familiar with data.table and not sure, if I can nest my conditions on cumsum in on data.table like that.
Any suggestions?