Getting a numeric graphics handle for a patch?

I need to get a numeric handle to a patch object in R2017A. Both get(gca,'Children') and findobj return a struct with all the graphic object properties except the handle. A post referring to R2014 mentions I can get this using the 'Number' property, but this doesn't seem to exist anymore. Here is the link to the article: https://www.mathworks.com/help/matlab/graphics_transition/graphics-handles-are-now-objects-not-doubles.html#budq3uo-1

This seems like it should be simple but I am stuck!

Thanks, Alan

[Steven Lord]

Why do you need the numeric handle?

[alan cheville]

I need to create a unique numeric identifier for a graphics object.

Answer 1

[Walter Roberson]

double() the handle. You can handle() the result to get back the object.

Note: the Number property applies only for figures.

>> aaa = patch(nan,nan,nan)
aaa = 
  Patch with properties:

      FaceColor: 'flat'
      FaceAlpha: 1
      EdgeColor: [0 0 0]
      LineStyle: '-'
          Faces: 1
       Vertices: [NaN NaN]

    Show all properties
  >> double(aaa)
  ans =
             0.0001220703125

>> handle(ans)
ans = 
  Patch with properties:

      FaceColor: 'flat'
      FaceAlpha: 1
      EdgeColor: [0 0 0]
      LineStyle: '-'
          Faces: 1
       Vertices: [NaN NaN]

    Show all properties

[alan cheville]

Brilliant, that worked well. Thanks for the fast response.