Reservoir Sampling
Reservoir Sampling
Reservoir SamplingDescription
The Reservoir Sampling transform allows you to sample a fixed number of rows from an incoming data stream when the total number of incoming rows is not known in advance.
The transform uses uniform sampling; all incoming rows have an equal chance of being selected.
This transform is particularly useful when used in conjunction with the ARFF output transform in order to generate a suitable sized data set to be used by WEKA.
The reservoir sampling transform uses Algorithm R by Jeffery Vitter.
Hop Engine
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Spark
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Flink
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Dataflow
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Options
Transform name
Name of the transform this name has to be unique in a single pipeline.
Sample size
Select how many rows to sample from an incoming stream. Setting a value of 0 will cause all rows to be sampled; setting a negative value will block all rows.
Random seed
Choose a seed for the random number generator. Repeating a pipeline with a different value for the seed will result in a different random sample being chosen.
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