如何在满足某些条件后调用矩阵中的行？-Howtocalltherowinamatrixaftercertaincriteriahasbeenmet?

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The rle function (run length encoding) can be combined with the diff function to identify the locations where the differences are 1 and have length greater than or equal to 2. The diff-operation actually shifts the names by 1 so there's no need to add 1 to the names()-result. That character result can then be used to index a matrix with rownames:

rle函数（运行长度编码）可以与diff函数结合使用，以识别差异为1且长度大于或等于2的位置。差异操作实际上将名称移动1，因此无需添加1到名字（） - 结果。然后可以使用该字符结果来索引具有rownames的矩阵：

> rle( diff(mat[,'row']))
Run Length Encoding
  lengths: Named int [1:19] 1 2 1 1 1 1 1 1 1 1 ...
 - attr(*, "names")= chr [1:19] "42" "45" "55" "56" ...
  values : Named num [1:19] 5 1 2 10 1 2 1 2 4 7 ...
 - attr(*, "names")= chr [1:19] "41" "43" "45" "55" ...
> rdiffs <- rle( diff(mat[,'row']))
> rdiffs$lengths >= 2
   42    45    55    56    58    59    61    65    72    73    76    77 
FALSE  TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE  TRUE FALSE 
   82    93    94   101   104   135       
 TRUE FALSE FALSE  TRUE FALSE FALSE FALSE 

> attr(rdiffs$lengths,"names")[ rdiffs$lengths >= 2 ]
[1] "45"  "76"  "82"  "101"

> mat [ attr(rdiffs$lengths,"names")[ rdiffs$lengths >= 2 & rdiffs$values == 1] , ]
    row day   Tx    Hx   Tn
45   45  14 29.1 37.34 19.0
76   76  15 31.4 39.47 18.4
82   82  21 32.0 38.62 19.3
101 101   9 33.0 39.00 17.4

I'll also put in a reproducible example:

我还将提供一个可重现的例子：

dn <- scan()
36   36   5 32.5 37.78 16.3
41   41  10 33.3 41.46 20.5
42   42  11 31.7 41.57 21.2
43   43  12 31.3 39.03 22.2
45   45  14 29.1 37.34 19.0
55   55  24 33.7 41.77 16.4
56   56  25 29.3 38.07 15.9
58   58  27 35.0 41.07 15.3
59   59  28 34.3 40.37 18.5
61   61  30 33.5 40.34 14.9
65   65   4 31.0 37.24 11.4
72   72  11 32.6 40.00 16.2
73   73  12 33.8 40.25 16.8
74   74  13 34.7 41.04 18.6
76   76  15 31.4 39.47 18.4
77   77  16 27.7 37.30 18.4
78   78  17 27.9 38.36 22.3
79   79  18 32.9 42.07 20.1
82   82  21 32.0 38.62 19.3
93   93   1 28.6 37.55 18.1 
94   94   2 30.3 39.71 15.3
95   95   3 32.7 39.46 17.5
101 101   9 33.0 39.00 17.4
104 104  12 27.5 37.10 16.7
135 135  12 32.6 38.45 17.7
mat <- matrix(dn, ncol=6, byrow=TRUE)
mat<- mat[, -1]
colnames(mat) <- c('row', 'day',  'Tx',    'Hx',   'Tn')
rownames(mat) <-mat[,'row']