Question

我有一个数据框，对3个变量a，b和c

有一些非负值（排序类型）

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        rq = Volley.newRequestQueue(this);
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我想计算一个新变量＆＃34; 优先级＆＃34;它给出了应该选择变量的优先级

x <- data.frame(cbind(ID=c(1,2,3,4,5),a=c(14,20,0,14,0),b=c(20,0,20,12,0),c=c(12,12,0,0,20)))

+----------------+
|ID  | a | b | c |
+----------------+
|1   |14 |20 |12 |
|2   |20 |0  |12 |
|3   |0  |20 |0  |
|4   |14 |12 |0  |
|5   |0  |0  |20 |
+----------------+

有关如何在R中创建此类输出的任何帮助都深受赞赏。

Answer 1

这是尝试使用长格式然后加入到原始数据集

的尝试

library(data.table) 
indx <- melt(setDT(x), 1L)[value > 0, 
             paste(variable[order(-value)], collapse = ">"), 
             by = ID]
x[indx, priority := i.V1, on = "ID"]
x
#    ID  a  b  c priority
# 1:  1 14 20 12    b>a>c
# 2:  2 20  0 12      a>c
# 3:  3  0 20  0        b
# 4:  4 14 12  0      a>b
# 5:  5  0  0 20        c

这基本上是“融化”数据ID，过滤大于零的值，按ID分配/粘贴列名

Answer 2

这样吗？

apply(x[-1], 1, function(x) paste(names(x)[x!=0][order(x[x!=0], 
    decreasing = T)], collapse = ">"))
[1] "b>a>c" "a>c"   "b"     "a>b"   "c"

Answer 3

colLabels=c("a","b","c")
sorting=function(x){
      sortedInd = (sort.int(x, index.return = TRUE, decreasing = TRUE))$ix
      sortedLabels = colLabels[sortedInd]
      paste(sortedLabels, collapse = ">")
}

x$priority = apply(x[,-1],1,sorting)

sortedInd返回每个已排序行的索引，然后将其输入colLabels以获取相应的标签。然后使用折叠将标签组合为“＆gt;”在粘贴

根据R中的排名减少变量（列）的顺序

3 个答案: