[R] mean

[kjetil halvorsen]

> x <- matrix(1:100, 10)
> x
      [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
 [1,]    1   11   21   31   41   51   61   71   81    91
 [2,]    2   12   22   32   42   52   62   72   82    92
 [3,]    3   13   23   33   43   53   63   73   83    93
 [4,]    4   14   24   34   44   54   64   74   84    94
 [5,]    5   15   25   35   45   55   65   75   85    95
 [6,]    6   16   26   36   46   56   66   76   86    96
 [7,]    7   17   27   37   47   57   67   77   87    97
 [8,]    8   18   28   38   48   58   68   78   88    98
 [9,]    9   19   29   39   49   59   69   79   89    99
[10,]   10   20   30   40   50   60   70   80   90   100
> apply(x,2,mean)
 [1]  5.5 15.5 25.5 35.5 45.5 55.5 65.5 75.5 85.5 95.5
> apply(x,1,mean)
 [1] 46 47 48 49 50 51 52 53 54 55


luca laghi wrote:
> 
>  Greetings,
> a little question:
> if I heve got a matrix with 10 columns, how do I produce a 10 elements
> vector with the average of each column?
> Thank you,
> Luca
> 
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