[R] mean for each row

[Bill.Venables at csiro.au]

You need to omit the last column, though:

RowM <- rowMeans(x[, -ncol(x)])

for example.



-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
On Behalf Of Matthias Kohl
Sent: Monday, 17 March 2008 4:14 PM
To: Hesen Peng
Cc: R help forum
Subject: Re: [R] mean for each row

or rowMeans ...
Matthias

Hesen Peng wrote:
> How about rowSums(x)/ncol(x), where x is the matrix?
>
>
> On Mon, Mar 17, 2008 at 1:48 PM, Roslina Zakaria <zroslina at yahoo.com>
wrote:
>   
>>   Hi r-users,
>>  How do find the mean for each row? Thank you in advance for your
help.
>>
>>
>>           1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 Day
Totals
>>  1            0.0  0.0  0.0  0.0  0.6  0.0  8.4  0.0 29.4  0.0
38.4
>>  2            0.0  0.0  1.8  0.0 22.4  0.0  0.2  0.4  0.8  0.0
25.6
>>  3            7.8  0.0  0.0 17.6  1.4  0.0  0.0  0.0  0.0  0.0
26.8
>>  4            2.2  0.8  0.4  0.0  0.2 11.2  1.4 33.2  0.0  0.0
49.4
>>  5            0.2  1.8  0.0  1.0  0.0  0.2  0.0 12.2  0.0 19.2
34.6
>>  6            0.0  0.0  0.0  1.0  0.0  0.0  0.0  2.2  0.0 14.6
17.8
>>  7            0.0  0.0  0.0  0.0  3.6  0.2  0.0  2.0  0.0  0.2
6.0
>>  8            0.0  0.0 10.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0
10.0
>>  9            0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0
0.0
>>  10           1.0  1.4  0.0  0.0  0.0  1.0  0.4  0.0  0.0  0.0
3.8
>>  11           0.0  8.2  0.0  0.0  0.0  0.0  8.4  0.0  0.0  0.4
17.0
>>  12          10.8  0.8  0.0  0.0  0.0  0.0  1.0  0.0  0.0  4.2
16.8
>>  13          32.8  0.0  0.0  0.8  0.0  0.0  0.0  0.0  0.2  0.2
34.0
>>  14           1.0  0.0  1.6  0.2  0.0  0.0  0.0  0.0  0.0  0.0
2.8
>>  15           0.0  0.0  0.0  2.2  1.4  0.0  0.0  0.0  0.0  0.0
3.6
>>  16           0.6  0.0  0.0  0.6 22.0  0.0  0.0  0.0  0.0  0.0
23.2
>>  17           0.0  0.0  0.0  0.0  0.0  0.0  2.8  0.0  0.0  0.0
2.8
>>  18           2.8  0.0  0.0  0.0  0.0  0.0  8.2  0.0  0.0  8.2
19.2
>>  19           0.0  0.0  0.0  0.0  0.0  0.2  0.0  0.0  0.0  0.2
0.4
>>  20           0.0  8.2  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0
8.2
>>  21           0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0
0.0
>>  22           0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.4
0.4
>>  23           0.0  0.0  0.0  0.0  0.0  0.0  0.0  1.2  0.0  0.0
1.2
>>  24           0.0  0.0  0.0  0.0  1.0  0.0  0.0  2.0  8.2  0.0
11.2
>>  25           3.2  0.0  0.0  0.6  0.6  0.0  0.0  0.0 11.8  0.0
16.2
>>  26           0.0  0.0 26.2  0.0 12.6  0.0  0.0  2.2  0.0  0.0
41.0
>>  27           0.2  0.0 10.6  0.0  1.2  0.0  0.0  1.8  0.0  0.0
13.8
>>  28           0.0  4.0  0.0  5.8  0.0  0.0  0.0  0.0  0.0  0.0
9.8
>>  29           0.2 12.4  0.0  0.0  0.0  0.0  0.0  0.0  0.0  0.0
12.6
>>  30           0.0  2.6  0.0  0.0  2.2  0.0  0.0  0.0  0.0  0.0
4.8
>>  31           0.0  0.0  0.6  0.0  0.8  0.0  0.0  0.0  4.8  0.0
6.2
>>  Year Totals 62.8 40.2 51.2 29.8 70.0 12.8 30.8 57.2 55.2 47.6
457.6
>>
>>
>>
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____________
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>>
>>  ______________________________________________
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>>     
>
>
>
>   

-- 
Dr. Matthias Kohl
www.stamats.de

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