Get information about all dimensions in unit registry
[dimensions, units] = pm_getdimensions
[dimensions, units] = pm_getdimensions returns
all dimensions registered in the unit registry in a cell array ,
Their corresponding units are returned in the
List all dimensions currently defined in the registry:
pm_getdimensions ans = 'charge' 'length' 'mass' 'mole' 'temperature' 'time'