MATLAB: Does ishandle(0) return 1

handle graphicshandlesishandle

I'm not too familiar with graphics handles. Hopefully this is a quick question.

Is it to simplify checks when setting or getting defaults, e.g. for set(0,'blah','blah')?

Best Answer

Hi,

yes 0 is the handle to the default settings/properties and because of this ishandle(0) returns 1.

Related Solutions

MATLAB: Unexpected behaviour from ishandle()

On MATLAB versions prior to R2016b zero is the handle to the graphics root (i.e. the parent of all graphics figures):

https://www.mathworks.com/help/matlab/graphics-objects.html

For compatilbility using zero is still permitted in later versions.

https://www.mathworks.com/help/matlab/ref/groot.html

MATLAB: Getting a numeric graphics handle for a patch

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

Best Answer

Related Solutions

MATLAB: Unexpected behaviour from ishandle()

MATLAB: Getting a numeric graphics handle for a patch

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