class.aggregator: A Simple Class for Aggregators

Description Details Creating Objects Slots Methods See Also


A class of objects designed to help aggregate calculations over an iterative computation. The aggregator consists of three objects. An environment to hold the values. A function that sets up an initial value the first time an object is seen. An aggregate function that increments the value of an object seen previously.


This class is used to help aggregate different values over function calls. A very simple example is to use leave one out cross-validation for prediction. At each stage we first perform feature selection and then cross-validate. To keep track of how often each feature is selected we can use an aggregator. At the end of the cross-validation we can extract the names of the features chosen from aggenv.

Creating Objects

new('aggregator', aggenv = [environment], initfun = [function], aggfun = [function])



Object of class 'environment', holds the values between iterations


Object of class 'function' specifies how to initialize the value for a name the first time it is encountered


Object of class 'function' used to increment (or perform any other function) on a name



Used to access the environment of the aggregator


Used to access the function that aggregates


Used to access the initializer function

See Also


Biobase documentation built on Nov. 8, 2020, 6:52 p.m.