sampleBy(doBy) | R Documentation |
Sampling from a data frame
Description
A data frame is split according to some variables in a formula, and a sample of a certain fraction of each is drawn.
Usage
sampleBy(formula, frac = 0.1, replace=FALSE, data = parent.frame(),systematic=FALSE)
Arguments
formula |
A formula defining the grouping of the data frame |
frac |
The part of data to be sampled. |
replace |
Is the sampling with replacement |
data |
A data frame |
systematic |
Should sampling be systematic. |
Details
If systematic=FALSE (default) then frac gives the fraction of data sampled. If systematic=TRUE and frac=.2 then every 1/.2 i.e. every 5th observation is taken out.
Value
A data frame
Author(s)
Søren Højsgaard, [email protected]
See Also
orderBy
,
summaryBy
,
transformBy
,
splitBy
,
Examples
data(dietox) sampleBy(formula = ~Evit+Cu, frac=.1, data = dietox)
[Package doBy version 1.9 Index]