Unclear error message when passing cell-array to controller object without outputs

[AndreasHempel]

When passing a cell array of parameter values to a controller object without requesting output arguments, e.g. (based on the mpc_parametric_inequalities.m example)

controller{ {X(:,k), r1, r2} }

the call fails with the cryptic error message

Error using numel
Bad subscripting index.

On the other hand, handing the parameter values to the controller not as a cell array, i.e.

controller{ X(:,k), r1, r2 }

works and prints the values of the first two output arguments (requested solver output and exitflag) to the console like so:

>> controller{ X(:,k), r1, r2 }

ans =

  -6.5191e-07


ans =

     1

A solution would be to detect the error when calling the controller object and printing an appropriate error message. Probably #11 should be resolved first since it seems related.

[GianUlli]

This was a bug. It was fixed with commit 8504061. Had something to do with the way Matlab determines the output size when indexing a class.