help bsample dialog: bsample
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Title
[R] bsample -- Sampling with replacement
Syntax
bsample [exp] [if] [in] [, options]
where exp is a standard Stata expression; see exp.
options description
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strata(varlist) variables identifying strata
cluster(varlist) variables identifying resampling clusters
idcluster(newvar) create new cluster ID variable
weight(varname) replace varname with frequency weights
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Menu
Statistics > Resampling > Draw bootstrap sample
Description
bsample draws random samples with replacement from the data in memory.
exp specifies the size of the sample, which must be less than or equal to
the number of sampling units in the data. The observed number of units
is the default when exp is not specified.
For a simple random sample (SRS) of the observations, exp must be
less than or equal to _N (the number of observations in the data;
see _N).
For stratified SRS, exp must be less than or equal to _N within the
strata identified by the strata() option.
For clustered sampling, exp must be less than or equal to N_c (the
number of clusters identified by the cluster() option).
For stratified sampling of clusters, exp must be less than or equal
to N_c within the strata identified by the strata() option.
Observations that do not meet the optional if and in criteria are dropped
(not sampled).
Options
strata(varlist) specifies the variables identifying strata. If strata()
is specified, bootstrap samples are selected within each stratum.
cluster(varlist) specifies the variables identifying resampling clusters.
If cluster() is specified, the sample drawn during each replication
is a bootstrap sample of clusters.
idcluster(newvar) creates a new variable containing a unique identifier
for each resampled cluster.
weight(varname) specifies a variable in which the sampling frequencies
will be placed. varname must be an existing variable, which will be
replaced. After bsample, varname can be used as an fweight in any
Stata command that accepts fweights, which can speed up resampling
for commands like regress and summarize. This option cannot be
combined with idcluster().
By default, bsample replaces the data in memory with the sampled
observations; however, specifying the weight() option causes only the
specified varname to be changed.
Examples
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. webuse bsample1
. bsample 200
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. webuse bsample1, clear
. bsample 200, strata(female)
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. webuse bsample1, clear
. bsample 200 if female
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Also see
Manual: [R] bsample
Help: [R] bootstrap, [R] bstat, [R] simulate, [D] sample
