Error while prior austenite grain reconstruction

[Saurabh Pawar]

Dear all,

I am trying to reconstruct prior austenite grains from EBSD data measured on martensitic phase. The code is running fine for many cases but for one case it is showing the following error.

>>>Error using convhull

>>>Error computing the convex hull. Not enough unique points specified.

>>>Error in spatialDecomposition>calcBoundary (line 96)

      k = convhull(x,y);

>>>Error in spatialDecomposition (line 26)

  dummyCoordinates = calcBoundary(X,unitCell,varargin{:});

>>>Error in EBSD/calcGrains (line 26)

[V,F,I_FD] = spatialDecomposition([ebsd.prop.x(:), ebsd.prop.y(:)],ebsd.unitCell,varargin{:});

>>>Error in PAG_MTEX (line 36)

[grains,ebsd.grainId] = calcGrains(ebsd('Ferrite'),'angle',3*degree);

Below is my initial block of code for doing this...

%% Specify File Names

% path to files

pname = 'C:\Users\Saurabh\Desktop\EBSD\Experiment\Attempt_2\5kA\Initial_5kA\PAG';

% which files to be imported

fname = [pname '\cropped.ang'];

%% Import the Data

% create an EBSD variable containing the data

ebsd = EBSD.load(fname,CS,'interface','ang',...

  'convertEuler2SpatialReferenceFrame');

[grains,ebsd.grainId] = calcGrains(ebsd('indexed'),'angle',3*degree);  %Error in this line

% remove small grains

ebsd(grains(grains.grainSize < 4)) = [];

please help to resolve this issue...

Thanks

Regards,

Saurabh Pawar