汇总数据框

Question

I have the following database. How can I ignore the empty cell and compress into one row ??

M = data.frame( Name = c('name','name'), Col1 = c("",1) , Col2 = c(2,""))
M$Col1 <- as.character(M$Col1)
M$Col2 <- as.character(M$Col2)

Thank You

Answer 1

As @Nicola already expressed in the comments:

M2 <- aggregate(.~Name, M, paste, collapse="")

is giving the desired output:

> M2
  Name Col1 Col2
1 name    1    2

Answer 2

您可以使用聚合函数来解决您的问题。

aggregate(M[c("Col1","Col2")], list(M$Name), max, na.rm = TRUE)

Answer 3

Here is a dplyr solution

library(dplyr)
M %>%
    group_by(Name) %>%
    summarise(Col1 = paste0(Col1, collapse = ''),
              Col2 = paste0(Col2, collapse = ''))

##     Name  Col1  Col2
##   (fctr) (chr) (chr)
## 1   name     1     2

This works based on the input data without having to convert the columns to characters

M = data.frame( Name = c('name','name'), Col1 = c("",1) , Col2 = c(2,""))