We do not perform any data sampling for the 2D CNNs. Since the hyperparameter tuning doesn't consider the default hyperparameters, we want to train a model with the default hyperparameters, just in case the default parameters perform best.
The default 2D CNNS can be trained with the trainCNN2dManualParams
function.
For example, here's the code used to train the default 3-layer 2D CNN:
p.FilterSize=[16,2;,16,2;16,2];
p.Nfilters=[20,20,20];
trainCNN2dManualParams(@CNN2d,UseGPU=true,ClassifierParams=p)