I think you can do this with the current interface. The convergence criterion object stays around, so you should be able to simply store the current aggregator value in a field (when the check is invoked). Any round but the first could compare against that field.
On Fri, Sep 4, 2015 at 2:25 PM, Andres R. Masegosa <and...@cs.aau.dk> wrote: > Hi, > > > I trying to implement some machine learning algorithms that involve > several iterations until convergence (to a fixed point). > > My idea is to use a IterativeDataSet with an Aggregator which produces > the result (i.e. a set of parameters defining the model). > > From the interface "ConvergenceCriterion", I can understand that the > convergence criterion only depends on the result of the aggregator in > the current iteration (as happens with the DoubleZeroConvergence class). > > However, it is more usual to test convergence by comparing the result of > the aggregator in the current iteration with the result of the > aggregator in the previous iteration (one usually stops when both > results are similar enough and we have converged to a fixed point). > > I guess this functionality is not included yet. And this is because the > convergence criteria of flink implementations of K-Means and Linear > Regression is to stop after a fixed number of iterations. > > > Am I wrong? > > > Regards > Andres >
