I use the code below to calculate the mean, upper and lower confidence intervals of multiple variables at once.
library(gmodels)
library(purrr)
dfci <- df %>%
group_by(group) %>%
dplyr::summarize(across(everything(),
.fns = list(mean = ~ mean(.x, na.rm = TRUE, trim = 4),
ci = ~ ci(.x, confidence = 0.95, alpha = 0.05, na.rm = T))))
#dfci <- dfci[-(13:16),] # remove additional rows
write.csv(dfci, file="dfci.csv")
Sample data:
Group| A_pre | A_post | B_pre | B_post
0 20 21 20 23
1 30 10 19 11
2 10 53 30 34
1 22 32 25 20
2 34 40 32 30
0 30 50 NA 40
0 39 40 19 20
1 40 NA 20 20
2 50 10 20 10
0 34 23 30 10
As I have over 50 "pre" and "post" variables i.e., >100 variables, is it possible to combine the outputs from the three desired cells (mean, lower and upper ci) into one so I am not manually combining all of them?
I tried pivoting into long after the ci calculations but doesn't work:
library(reshape2)
dfci <- df %>%
group_by(group) %>%
summarize(across(everything(),
.fns = list(mean = ~ mean(.x, na.rm = TRUE, trim = 4),
ci = ~ ci(.x, confidence = 0.95, alpha = 0.05, na.rm = TRUE))))
dfci <- melt(dfci, id.vars = "group")
dfci <- dcast(dfci, group + variable ~ variable)
write.csv(dfci, file = "dfi.csv", row.names = FALSE)
Unfortunately the earlier answers did not work as they repeated the same ci throughout.
This code does the job:
library(dplyr)
dfci <- df %>%
group_by(group) %>%
summarise(across(everything(), list(
mean = ~ mean(., na.rm = TRUE, trim = 4),
ci = ~ { # OWN CI FUNCTION
se <- sqrt(var(., na.rm = TRUE) / sum(!is.na(.)))
mean_val <- mean(., na.rm = TRUE)
lower <- mean_val - qt(0.975, df = sum(!is.na(.))) * se
upper <- mean_val + qt(0.975, df = sum(!is.na(.))) * se
paste0("[", round(lower, 2), ", ", round(upper, 2), "]")
}
), .names = "{.col}_{.fn}")) %>%
ungroup()