Error while generating Symbolic Gravity Load Vector

What steps will reproduce the problem?
1. Create a 5 DOF robot arm object using SerialLink class, with standard DH 
convention. (A notepad file with all the commands is attached herewith)
2. Then create another object, say with the name 'rob', using the CodeGenerator 
class.
3. Then type the command >> rob.geneverything()

What is the expected output? What do you see instead?

When it comes to the point where "gravity load vector" needs to be generated, 
it gives the following error:

>>
09-Jan-2014 04:58:25    Deriving gravitational load vectorError using mupadmex
Error in MuPAD command: Array sizes must match.

Error in sym/privBinaryOp (line 1694)
            Csym = mupadmex(op,args{1}.s, args{2}.s, varargin{:});

Error in sym/minus (line 7)
X = privBinaryOp(A, B, 'symobj::zip', '_subtract');

Error in SerialLink/rne_dh (line 211)
                t = nn.'*(R.'*z0) + ...

Error in SerialLink/rne (line 75)
            [varargout{1:nargout}] = rne_dh(robot, varargin{:});

Error in SerialLink/gravload (line 42)
        tg = rne(robot, q, zeros(size(q)), zeros(size(q)));

Error in CodeGenerator/gengravload (line 52)
G = CGen.rob.gravload(q);
<<

What version of the product are you using? On what operating system?

Robotics Toolbox (release 9.8)
MATLAB R2012a
Microsoft Windows 7 (64-bit)

Please provide any additional information below.

With modified DH parameters, the symbolic code generator only gives the 
"forward kinematics" and after that it gives an error which is somewhat similar 
to the above mentioned error, which says something like: "input can not be 
converted to double..."
That's why I shifted to standard DH convention and then it generated the 
symbolic expressions up till the point where gravity load vector was supposed 
to be computed symbolically but it failed due to the error.

Original issue reported on code.google.com by umair4...@gmail.com on 9 Jan 2014 at 5:03

kalyousefi / matlab-toolboxes-robotics-vision

Error while generating Symbolic Gravity Load Vector #19