Synopsis
Creates a stratified sample from an example set by drawing a fraction.
Description
Stratified sampling operator. This operator performs a random sampling of a given fraction. In contrast to the simple sampling operator, this operator performs a stratified sampling for data sets with nominal label attributes, i.e. the class distributions remains (almost) the same after sampling. Hence, this operator cannot be applied on data sets without a label or with a numerical label. In these cases a simple sampling without stratification is performed.
Input
- example set input: expects: ExampleSetMetaData: #examples: = 0; #attributes: 0
Output
- example set output:
- original:
Parameters
- sample: Determines how the amount of data is specified.
- sample size: The number of examples which should be sampled
- sample ratio: The fraction of examples which should be sampled
- use local random seed: Indicates if a local random seed should be used.
- local random seed: Specifies the local random seed