robotology/yarp-matlab-bindings

ERROR using yarpMEX - Yarp MatLab bindings on MATLAB R2020b when mexErrMsgIdAndTxt is invoked

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giovannipizzolante commented

Hi @traversaro , when I try to go on for checking the bindings installation, as suggested here, when I type yarpVec.fromMatlab([1;2;3]) the following error is returned:

Error using yarpMEX
The error message identifier is invalid.

Error in yarp.Vector/fromMatlab (line 163)
      [varargout{1:nargout}] = yarpMEX(2590, self,
      varargin{:});

Error in SwigRef/subsref (line 33)
        [varargout{1:nargout}] =
        builtin('subsref',self,s);

Do you know how to solve this?

traversaro commented

I do not know in particular how to approach this problem, it could be due to some change in recent MATLAB R2020b that is not properly supported in SWIG. Anyhow, it seems to be similar to robotology/robotology-superbuild#515 . Perhaps @lnobile could let us know how he worked around this, for example I guess you can set the elements of a YARP vector also with the setVal method?

lnobile commented

Hi everybody,
I ended up using bottles to write data on a port, an example:

 % writing to port example:

         port_points_opti = Port;                                        % create port
         port_points_opti.open('points_opti:o');                  % open port with desired name

          b_points_opti = Bottle();                                       % create bottle
          b_points_opti.clear();
          for kk = 1:size(opti_points_matrix,1)
              b_points_opti.addDouble(opti_points_mat(kk,1));  % add elements to bottle
          end
          port_points_opti.write(b_points_opti)                   % write to port
  • 👍2
traversaro commented

Apparently, the error for some reason is in https://github.com/robotology/yarp/blob/5313b2defd8be7237567ea56eca8dde93dfc8121/bindings/matlab/vectors_fromTo_matlab.i#L59, in the use of the mexErrMsgIdAndTxt function. However, that part of the code is reached as, differently from the iDynTree version, the yarp's fromMatlab already wants to be the YARP vector of the correct size. So, without any further fix, this version of the snippet should work fine:

yarpVec = yarp.Vector();
yarpVec.resize(3);
yarpVec.fromMatlab([1;2;3]);
yarpVec.toMatlab()

cc @giovannipizzolante @lnobile

If you want to test it again, you can check the one line installation procedure in https://github.com/robotology/robotology-superbuild/blob/master/doc/matlab-one-line-install.md .

traversaro commented

robotology/yarp#2564 was merged, now we just need to re-generate the bindings.