If "train", "valid", and "xval" parameters are FALSE (default), then the training totss value is returned. If more than one parameter is set to TRUE, then a named vector of totss' are returned, where the names are "train", "valid" or "xval".
h2o.totss(object, train = FALSE, valid = FALSE, xval = FALSE)
Retrieve the training total sum of squares
Retrieve the validation total sum of squares
Retrieve the cross-validation total sum of squares