Simply put,dgRMatrixobjects are just not commonly used, and as much as I would prefer to defer responsibility for the format choice to the user, this is a case where we really need to align to the expectations of the rest of the ecosystem that consumes the SCEs thatzellkonverterwill produc...
all input cell arrays must be same data type. Might be due to the '31.1.2013' in the 3. column...? So that relates to you question - no, not all are numbers.)
Matlab (and Julia) try to give both speed and interactive use – they come to the table as the prototyping languages for high performance computing. They are meant to take big matrices and crunch away. They too are domain specific not general purpose languages, but the set of people interest...