read.csv() reads the data.frame OK readr::read_csv() for the same data.frame fails, why?

below, when I read in my data.frame using readr::read_csv(), my subsequent code produces NA for yi.

But when I read in my data.frame using Base R’s read.csv(), my subsequent code correctly computes yi.

I wonder what’s going on?

library(tidyverse)

d <- read_csv("https://raw.githubusercontent.com/fpqq/w/main/n.csv")
d2 <- read.csv("https://raw.githubusercontent.com/fpqq/w/main/n.csv")


d %>% group_by(study) %>%  # change `d` to `d2` and compare the results
  mutate(n = unlist(mean(c(nT,nC))),
         N = nT+nC,
         w = (nT+nC-2)*.8,
         icc = .15,
          yi = ifelse(assign_type=="group", yi*w, yi)
  ) %>% ungroup

>Solution :

by default read_csv() converts empty strings to NA.

Try d <- read_csv("https://raw.githubusercontent.com/fpqq/w/main/n.csv", na = c("NA"))

Both data sets should be the same now.