列中的R数据表计数值

library(data.table)
data=data.table("cat"=c(0,5,NA,0,0,0),
"fox"=c(2,0,NA,NA,7,0))
data[, Count0 := cat + fox]
data$WANT = c(1,1,NA,1,1,2)

library(data.table)
data=data.table("cat"=c(0,5,NA,0,0,0),
"fox"=c(2,0,NA,NA,7,0))
cols <- c("cat","fox")
data[,count0:=rowSums(data[,.SD,.SDcols=cols]==0,na.rm = TRUE)]
data[rowMeans(is.na(data[,..cols]))==1,count0:=NA_integer_]

^{由reprex包(v0.3.0(于2020-04-25创建}

library(data.table)
cols <- c("cat","fox")
data[,ans := rowSums(.SD == 0, na.rm = TRUE), .SDcols = cols]
data[ans == 0, ans := NA]
data
#   cat fox and
#1:   0   2   1
#2:   5   0   1
#3:  NA  NA  NA
#4:   0  NA   1
#5:   0   7   1
#6:   0   0   2