R语言如何对每一行求和

最近遇到的小问题，需要对每一行的特定列求和 

 

文件实例 

df <- data.table(sample = c("test1","test2","test3"), value1 = c(1,2,3),value2 = c(2,4,5),value3 = c(2,1,7), value4 = c(4,2,1), group = c("Disease","Healthy","Disease"))

 

推荐一个集成R包 叫tidyverse

里面集成了非常多有用的R包 非常便利 

 

• 将特定列转换成行名　

df %>% 
  column_to_rownames(., var = "sample")

 

• 对value1到value3求和, 求和的方法非常多，这里使用mutate(增加新列) rowSum(求和) 来自dyplr 

df %>% 
  column_to_rownames(., var = "sample") %>%
  mutate(rowsum = rowSums(.[1:4]))

 

• 有时候给个变量，也可以识别，而不像data.table还需要加with=False

n <- 3 
df %>% 
  column_to_rownames(., var = "sample") %>%
  mutate(rowsum = rowSums(.[1:n]))

 

 

Ref : 

https://www.rdocumentation.org/packages/textshape/versions/1.7.1/topics/column_to_rownames

https://dplyr.tidyverse.org/reference/mutate.html