明显比ifelse方法快。创建初始 Dataframe 的代码如下所示：
# Replace NA in column StudyHours with the mean study hours # Drop NAs from our tibble anyNA(students) # Get the mean study hours using the accessor `$` # Get students who studied for more than the average number of hours # Mean grade of students who studied more than ...
ifelse所做的是创建一个大小为index的向量，当index为0时为0s，如果不是，则为上面的值，但它不会...
The dplyr package resembles the functionality in the purrr package, but it is designed for manipulating data frames. It will be loaded with the tidyverse p... J Mount,N Zumel 被引量: 0发表: 2016年 [R] dplyr - counting a number of specific values in each column - for all columns at ...
函数的使用方法： (1) 第一个参数是一个数据框。 (2) 随后的参数使用变量名称(不带引号)描述了...
summarise() reduces multiple values down to a single summary. arrange() changes the ordering of the rows.These all combine naturally with group_by() which allows you to perform any operation “by group”. You can learn more about them in vignette("dplyr"). As well as these single-table ...
Replace “=” in expressions with “:=”. This is the result: library(seplyr) starwars_mean <- function(my_var) { starwars %>% group_by_se(my_var) %>% summarize_se(c("mean_height" := "mean(height, na.rm = TRUE)", "mean_mass" := "mean(mass, na.rm = TRUE)", "count"...
当您想将函数应用于多个列时，请使用across：
Fixed protection error that occurred when creating a character column using grouped mutate() (#2971). Fixed a rare problem with accessing variable values in summarise() when all groups have size one (#3050). distinct() now throws an error when used on unknown columns (#2867, @foo-bar-...
window function Mutate uses window functions,functions that take a vector of values and return another vector of values,such as:dplyr::lead Copy with values shifted by 1. lag Copy with values lagged by 1. dense_rank Ranks with no gaps min_rank Ranks.Ties get min rank percent_rank Ranks ...