r - 获取矩阵排序

Question

我想将矩阵的值从最大到最小值进行排序和转换，就像在这个简单且可复制的示例中一样:

 #From :
 d<- c(-2,-34,25,0,13,0,25,-2,1)
 m<- matrix(d,3,3)
 m
     [,1] [,2] [,3]
[1,]   -2    0   25
[2,]  -34   13   -2
[3,]   25    0    1

# To:
m1
     [,1] [,2] [,3]
[1,]    5    4    1
[2,]    6    2    5
[3,]    1    4    3

#25: biggest number therefore -->(1)
#13: second biggest one ---> (2)
# ecc ...
#-34: the smallest one ---> (6)

有什么帮助吗？谢谢

Answer 1

您可以将 d 转换为因子，然后去掉级别。 (这意味着您不需要任何额外的包。)

m1 <- m
m1[]<-unclass(factor(d, levels = sort(unique(d), decreasing=TRUE)))
# alternative solutions from comments
# or levels=sort(-d), thanks, akrun
# or, to make it shorter: m1[] <- unclass(factor(-d))
# or, [eddi's suggestion using implicit conversions]: m1[] <- factor(-m) 
m1
#      [,1] [,2] [,3]
# [1,]    5    4    1
# [2,]    6    2    5
# [3,]    1    4    3