is mode choice a singular variable what is the singularity of mode choice what is the mode choice in r? which method is the singularity variable? which variable is used to construct mode choice? why is it difficult to specify a singularity for mode choice? r dgesv mode choice how to use mode choice in r r model definition singularity what is r singularity r how to find singularity of mode choice which of the following describes mode choice in r? can the model be singular which r variable is singular which type of mode choice variable is singular? which variable is singular which variable is singular what is singularity in multinomial data models is mode choice a singular variable what is singularity in mode choice