sample {SparkR}

R Documentation

Sample

Description

Return a sampled subset of this SparkDataFrame using a random seed. Note: this is not guaranteed to provide exactly the fraction specified of the total count of of the given SparkDataFrame.

Usage

sample(x, withReplacement = FALSE, fraction, seed)

sample_frac(x, withReplacement = FALSE, fraction, seed)

## S4 method for signature 'SparkDataFrame'
sample(x, withReplacement = FALSE, fraction, seed)

## S4 method for signature 'SparkDataFrame'
sample_frac(x, withReplacement = FALSE, fraction, seed)

Arguments

x	A SparkDataFrame
withReplacement	Sampling with replacement or not
fraction	The (rough) sample target fraction
seed	Randomness seed value. Default is a random seed.

Note

sample since 1.4.0

sample_frac since 1.4.0

See Also

Other SparkDataFrame functions: SparkDataFrame-class, agg(), alias(), arrange(), as.data.frame(), attach,SparkDataFrame-method, broadcast(), cache(), checkpoint(), coalesce(), collect(), colnames(), coltypes(), createOrReplaceTempView(), crossJoin(), cube(), dapplyCollect(), dapply(), describe(), dim(), distinct(), dropDuplicates(), dropna(), drop(), dtypes(), exceptAll(), except(), explain(), filter(), first(), gapplyCollect(), gapply(), getNumPartitions(), group_by(), head(), hint(), histogram(), insertInto(), intersectAll(), intersect(), isLocal(), isStreaming(), join(), limit(), localCheckpoint(), merge(), mutate(), ncol(), nrow(), persist(), printSchema(), randomSplit(), rbind(), rename(), repartitionByRange(), repartition(), rollup(), saveAsTable(), schema(), selectExpr(), select(), showDF(), show(), storageLevel(), str(), subset(), summary(), take(), toJSON(), unionAll(), unionByName(), union(), unpersist(), withColumn(), withWatermark(), with(), write.df(), write.jdbc(), write.json(), write.orc(), write.parquet(), write.stream(), write.text()

Examples

## Not run: 
##D sparkR.session()
##D path <- "path/to/file.json"
##D df <- read.json(path)
##D collect(sample(df, fraction = 0.5))
##D collect(sample(df, FALSE, 0.5))
##D collect(sample(df, TRUE, 0.5, seed = 3))
## End(Not run)

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