"Error displaying value" in Workspace browser for user defined object

I have a user defined object that I implemented concatenation for. However once it is concatenated the value field in the Workspace browser says "Error Displaying Value". The object works as expected in the code and has the necessary fields:

 whos('YM')
  Name      Size            Bytes     Class                  Attributes

YM        2x1              1822       DClab.ResponseModel

If anyone knows why this would be happening, I would really appreciate it.

Answer 1

[per isakson]

Isn't the message

    Error using disp
    Too many input arguments.

??

Which Matlab release?

--- Cont. ---

This behaves as expected (R20112a) and m is displayed correctly in the Workspace browser

    n1 = node(1,2);
    n2 = node(2,3);
    m = [ n1, n2 ];

.

    classdef node < handle
        properties
            x;
            y;
            bearing=0;
        end % properties
        methods
            function this = node(x,y)
                this.x=x;
                this.y=y;
            end%functions
        end%methods
    end %class

.

DClab is that a package?

.

--- Cont. ---

Moving node to a package folder causes no problems here.

.

--- Cont. ---

The error message is most likely generated by line 155 of the function, workspacefunc (R2012a). See the catch clause of the excerpt. I fail to reproduce the error; I leave it to you to find the exact behavior. It's no use that I guess. Thus

1. put a break (dbstop) twenty lines before "catch err"
2. run "workspacefunc( 'getshortvalue', DClab.ResponseModel )" in the command window
3. step through the code. Hopefully the problem will surface.
4. let the tech support know if the problem is not with your code.

Excerpt from the C:\Program Files\MATLAB\R2012a\toolbox\matlab\codetools\workspacefunc.m

     % Copyright 1984-2011 The MathWorks, Inc.
     .....
              end
              classinfo = [' ' getclass(var,true)];
              retstr = ['<', theSize, classinfo, '>'];
          end
      catch err %#ok<NASGU>
          retstr = getString(message(                                   ...
                   'MATLAB:codetools:workspacefunc:ErrorDisplayingValue'));
      end

[Chris Meissen]

Nope,

The error is inn the Workspace browser in the value field, it says "<Error displaying value>"

The disp command works fine:

disp(YM)

2x1 DClab.ResponseModel

Package: DClab

Properties:

type

name

model ...

It is Matlab 7.12.0 (R2011a)

Thanks

Chris

Answer 2

[Chris Meissen]

DClab is a package we created. I tested with other objects in the package and it works fine. It only has the problem when it is concatenating a certain class (ResponseModel) of objects. All the objects in the package inherit from the same superclass as well, so I don't understand why the behavior would be different.

I also tested with your code to make sure that was working and it ran as expected. If you have any ideas I would appreciate it.

Thanks, Chris

[per isakson]

See the addition to my answer