How to use imellipse for GUI?

Hi there,I'd like to extract a ellipse-like roi area, but the "imellipse" I noticed cannot include the theta angle, so I wonder if there is any solution so that an ellipse roi with user-defined theta&major axis&minor axis can be extracted. Or is there any function with circle-roi extraction and the circle can be transformed into an ellipse? Thanks! By the way, when I use the "imellipse" function in matlab 2012a, there are some errors, and the code i use for "imellipse" is the same as that in "imfreehand"(run successfully), so can anyone help me with this, thanks a lot. The code is as follows:

h_qupur = imfreehand(gca);

position_qupur = wait(h_qupur);

qupur_mask = createMask(h_qupur);

when the first line is placed by "h = imellipse(gca)" the errors appear:

Error: File: interp1q.m Line: 1 Column: 25 The input character is not valid in MATLAB statements or expressions.

Error in ellipseToPolygon (line 68) ts = interp1q(S(:),t(:),(1:(N-1))')';

Error in getEllipseVertices (line 20) [x,y] = ellipseToPolygon(a,b,cx,cy,delta);

Error in ellipseSymbol/updateView (line 157) vert = getEllipseVertices(h_axes,position);

Error in imrect>imrectAPI/updateView (line 432) draw_api.updateView(pos);

Error in imrect>imrectAPI/setPosition (line 376) updateView(position);

Error in imrect>imrectAPI/placeRect (line 350) setPosition([x_init y_init 0 0]);

Error in manageInteractivePlacement/buttonDownPlaceObject (line 206) completed = placementFcn(x_init,y_init);

Error in iptaddcallback/callbackProcessor (line 149) fun(varargin{:});

Error using waitfor Error while evaluating figure WindowButtonDownFcn

Error: File: interp1q.m Line: 1 Column: 25 The input character is not valid in MATLAB statements or expressions.

Error in ellipseToPolygon (line 68) ts = interp1q(S(:),t(:),(1:(N-1))')';

Error in getEllipseVertices (line 20) [x,y] = ellipseToPolygon(a,b,cx,cy,delta);

Error in ellipseSymbol/updateView (line 157) vert = getEllipseVertices(h_axes,position);

Error in imrect>imrectAPI/updateView (line 432) draw_api.updateView(pos);

Error in imrect>imrectAPI (line 300) updateView(position);

Error in imrect (line 83) [h_group,draw_api] = imrectAPI(varargin{:});

Error in imellipse (line 89) obj = obj@imrect(varargin{:},'DrawAPI',ellipseSymbol());

Error in VOG_mice (line 45) h_qupur = imellipse(gca);