The 'index' and 'ref' arguments of DecisionTree$tornado expect strategies to be given as lists of action edges. In the case of a strategy with only one action edge (as in, for example, a simple two choice decision tree), it seems redundant to have a wrap the action edge in a list(). Consider whether these arguments could accept single action edges as well as lists of edges.
Related, the description of these arguments should be clarified in the documentation to avoid confusion.
The 'index' and 'ref' arguments of DecisionTree$tornado expect strategies to be given as lists of action edges. In the case of a strategy with only one action edge (as in, for example, a simple two choice decision tree), it seems redundant to have a wrap the action edge in a list(). Consider whether these arguments could accept single action edges as well as lists of edges.
Related, the description of these arguments should be clarified in the documentation to avoid confusion.