如何删除r中没有超过3个值的行？

Question

这是我第一次问一个问题，希望我能得到你的帮助！ 我需要删除，使用R

基本上我需要摆脱50S，ABCC8的有只有一个或两个基因值的行，并ACAT1因为这些有< 3.

我期望的输出是

非常感谢你！

Answer 1

如果这是在data.frame中，则可以使用dplyr包进行一些操作。我们可以通过Genes和count将数据分组到多少个实例。然后我们只需设置过滤条件即可删除记录。

require(dplyr) 

df <- data.frame(
    Genes=c('50S' ,'abcb1' ,'abcb1' ,'abcb1' ,'ABCC8' ,'ABL' ,'ABL' ,'ABL' ,'ABL' ,'ACAT1' ,'ACAT1'), 
    Values=c(-0.627323448, -0.226358414, 0.347305901 ,0.371632631 ,0.099485307 ,0.078512979 ,-0.426643782, -1.060270668, -2.059157991, 0.608899174 ,-0.048795611) 
) 

#group, filter and join back to get subset the data 
df %>% group_by(Genes) 
    %>% summarize(count=n()) 
    %>% filter(count>=3) 
    %>% inner_join(df) 
    %>% select(Genes,Values) 

按@拉米亚的评论，可以简化它只是：

df %>% group_by(Genes) %>% filter(n()>=3) 

Answer 2

# generating data 
x <- c(NA, NA, NA, NA, 2, 3) # has n < 3! 
y <- c(1, 2, 3, 4, 5, 6) 
z <- c(1 ,2, 3, NA, 5, 6) 
df <- data.frame(x,y,z) 

colsToKeep <- c() # making empty vector I will fill with column numbers 
for (i in 1:ncol(df)) { # for every column 
    if (sum(!is.na(df[,i]))>=3) { # if that column has greater than 3 valid values (i.e., ones that are not na... 
colsToKeep <- c(colsToKeep, i) # then save that column number into this vector 
    } 
} 

df[,colsToKeep] # then use that vector to call the columns you want 

注意的是，R对待FALSE为0和TRUE为1，所以这是sum()功能是如何在这里工作。

Answer 3

另一种可能的解决方案通过使用table：

gene <- c("A","A","A","B","B","C","C","C","C","D") 
value <- c(seq(1,10,1)) 
df<-data.frame(gene,value) 
df 
    gene value 
1 A  1 
2 A  2 
3 A  3 
6 C  6 
7 C  7 
8 C  8 
9 C  9 

su<-data.frame(table(df$gene)) 
df_keep <-df[which(df$gene %in% su[which(su$Freq>2),1]),] 
df_keep 
    gene value 
1 A  1 
2 A  2 
3 A  3 
6 C  6 
7 C  7 
8 C  8 
9 C  9