[R] summary with variance / sd

[Søren Højsgaard]

You can use summaryBy() in the doBy package:
 
summaryBy(y+x~group, data=mydata, FUN=c(mean,sd))
 
Søren

________________________________

Fra: r-help-bounces at r-project.org på vegne af Jörg Groß
Sendt: sø 11-01-2009 22:38
Til: r-help at r-project.org
Emne: [R] summary with variance / sd



Hi,

I have a data frame and would like to have summary statistics for 
grouped data.

With summary() I get the central tendencies for the overall data.


How can I get descriptive statistics with variances and standard 
deviations?


for example my data.frame:

group   x       y
exp             2       4
exp             3       5
exp             2       4
control 1       2
control 2       3
control 1       2


now I want tables with summary statistics (variances included) for 
each group.

Is there an easy way to get this?

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