计算R中非零值之间的零出现次数

Nou*_*ura 2 r matrix

我有一个矩阵

mat <- matrix(c(64,76,0,0,78,35,45,0,0,4,37,0,66,46,0,0,0,0,3,0,71,0,28,97,0,30,55,65,116,30,18,0,0,143,99,0,0,0,0,0), nrow=4, byrow=T)

mat
     [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
[1,]   64   76    0    0   78   35   45    0    0     4
[2,]   37    0   66   46    0    0    0    0    3     0
[3,]   71    0   28   97    0   30   55   65  116    30
[4,]   18    0    0  143   99    0    0    0    0     0
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我想创建一个列表,该列表计算非零值之间的零出现次数

[[1]]
[1] 2 2

[[2]]
[1] 1 4 1

[[3]]
[1] 1 1

[[4]]
[1] 2 5
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Son*_*nny 5

所有你需要的是 rle

> apply(mat, 1, function(x) {
   rle(x)$length[rle(x)$values == 0]
 })
[[1]]
[1] 2 2

[[2]]
[1] 1 4 1

[[3]]
[1] 1 1

[[4]]
[1] 2 5
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  • 在这个例子中,速度并不重要,但你可以避免使用`with(rle(x),lengths [values == 0])来计算`rle(x)`两次. (3认同)