The "minibatchqueue" function converts the "categorical" values to "dlarray" by default for memory efficiency. However, the information of the categories is not lost. Each "integer" in the "dlarray" represents a category with respect to the alphabetical order of the categories names. In case you need the categorical value, you can just use the "dlarray" output as an index, as in the sample code below:
mbq = minibatchqueue(ds,MiniBatchSize=2);
minibatch = mbq.next
unique_cat = unique(data);
minibatch_cat=unique_cat(minibatch)
fprintf('mbq ouptus a mini batch data with type %s\n',class(minibatch_cat));
In case you want the "minibatchqueue" function to outcast "char" values instead of "integers" you can set the "OutputAsDlarray" property to "false" and the "OutputCast" to "char" as in the command below:
mbq = minibatchqueue(ds,MiniBatchSize=2,OutputAsDlarray=false,OutputCast='char');
