1.4 rowwise rowwise这个函数的名字就十分萌萌哒,其还有个兄弟(or姐妹)函数叫做colwise(源自plyr包),两者之间用法虽然不尽相同,却也有着相似的思想(一个按行分组一个按列分组好吗,要知道行和列在data.frame里面差距还是蛮大的哎)。 对,你理解的没错,其实就是apply(x,1,FUN)啦,但是apply的效率,你懂得……我...
今天接到一个群友的需求，有一张表的数据如图 1，他希望能通过 SQL 查询出图 2 的结果。
library(dplyr) # Summarise data into single row of values summarise(iris,avg = mean(Sepal.Length)) # Apply summary function to wach column summarise_each(iris,funs(mean)) # Count number of rows with each unique value of variable(with or without weights) count(iris,Species,wt = Sepal....
Summarise data into single row of values. dplyr::summarise_each(iris, funs(mean)) Apply summary function to each column. dplyr::count(iris, Species, wt = Sepal.Length) Count number of rows with each unique value of variable (with or without weights). ...
Error in n() : could not find function "n" indicates when functions like n(), row_number(), ... are not imported or prefixed. The easiest fix is to import dplyr with import(dplyr) in your NAMESPACE or #' @import dplyr in a roxygen comment, alternatively such functions can be ...
使用rowSums对每行求和（rowwise适用于任何聚合，但速度较慢）
使用rowSums对每行求和（rowwise适用于任何聚合，但速度较慢）
ofeachcallshouldbeomitted-thevalueofthepreviousstepwillbesubstituted inautomatically.Usechainand...whenworkinginteractive;usechain_q andcallswhencallingfromanotherfunction. envEnvironmentinwhichtoevaluationexpressions.Inordinaryoperationyou shouldnotneedtosetthisparameter. lhs,rhsAdatasetandfunctiontoapplytoit Details...
Example 1: row_number FunctionExample 1 explains how to use the row_number function in R. Have a look at the following R code:row_number(x) # Apply row_number function # 5 1 6 2 3 4The row_number function returns the ranking of each value of our input vector. Note that th...
dplyr: A grammar of data manipulation. Contribute to tidyverse/dplyr development by creating an account on GitHub.