License Plate Recognition Bounding Box - Need help with Bounding Box OverlapRatio Problem

I'm working on license plate recognition and I'm at the level of bounding the characters with a box. Here's the code I'm working with;

    % Detect MSER regions.
  [mserRegions] = detectMSERFeatures(I, ...
      'RegionAreaRange',[200 8000],'ThresholdDelta',4);

% First, convert the x,y pixel location data within mserRegions into linear
% indices as required by regionprops.
sz = size(I);
pixelIdxList = cellfun(@(xy)sub2ind(sz, xy(:,2), xy(:,1)), ...
    mserRegions.PixelList, 'UniformOutput', false);

% Next, pack the data into a connected component struct.
mserConnComp.Connectivity = 8;
mserConnComp.ImageSize = sz;
mserConnComp.NumObjects = mserRegions.Count;
mserConnComp.PixelIdxList = pixelIdxList;

% Use regionprops to measure MSER properties
mserStats = regionprops(mserConnComp, 'BoundingBox', 'Eccentricity', ...
    'Solidity', 'Extent', 'Euler', 'Image');

% Compute the aspect ratio using bounding box data.
bbox = vertcat(mserStats.BoundingBox);
w = bbox(:,1);
h = bbox(:,1);
aspectRatio = w./h;

% Get bounding boxes for all the regions
bboxes = vertcat(mserStats.BoundingBox);

% Convert from the [x y width height] bounding box format to the [xmin ymin
% xmax ymax] format for convenience.
xmin = bboxes(:,1);
ymin = bboxes(:,2);
xmax = xmin + bboxes(:,3) - 1;
ymax = ymin + bboxes(:,4) - 1;

% Expand the bounding boxes by a small amount.
expansionAmount = 0.02;
xmin = (1-expansionAmount) * xmin;
ymin = (1-expansionAmount) * ymin;
xmax = (1+expansionAmount) * xmax;
ymax = (1+expansionAmount) * ymax;

% Clip the bounding boxes to be within the image bounds
xmin = max(xmin, 1);
ymin = max(ymin, 1);
xmax = min(xmax, size(I,2));
ymax = min(ymax, size(I,1));

% Show the expanded bounding boxes
expandedBBoxes = [xmin ymin xmax-xmin+1 ymax-ymin+1];
IExpandedBBoxes = insertShape(I,'Rectangle',expandedBBoxes,'LineWidth',1);

figure
imshow(IExpandedBBoxes)
title('Expanded Bounding Boxes Text')

% Compute the overlap ratio
overlapRatio = bboxOverlapRatio(expandedBBoxes, expandedBBoxes);

% Set the overlap ratio between a bounding box and itself to zero to
% simplify the graph representation.
n = size(overlapRatio,1);
overlapRatio(1:n+1:n^2) = 0;

% Create the graph
g = graph(overlapRatio);

% Find the connected text regions within the graph
componentIndices = conncomp(g);
% Merge the boxes based on the minimum and maximum dimensions.
xmin = accumarray(componentIndices', xmin, [], @min);
ymin = accumarray(componentIndices', ymin, [], @min);
xmax = accumarray(componentIndices', xmax, [], @max);
ymax = accumarray(componentIndices', ymax, [], @max);

% Compose the merged bounding boxes using the [x y width height] format.
textBBoxes = [xmin ymin xmax-xmin+1 ymax-ymin+1];
% Remove bounding boxes that only contain one text region
numRegionsInGroup = histcounts(componentIndices);
textBBoxes(numRegionsInGroup == 1, :) = [];

% Show the final text detection result.
ITextRegion = insertShape(colorImage, 'Rectangle', textBBoxes,'LineWidth',3);

figure
imshow(ITextRegion)
title('Detected Text')
ocrtxt = ocr(I, textBBoxes);
[ocrtxt.Text]

Here's the feedback I keep getting from MATLAB; Undefined function 'bboxOverlapRatio' for input arguments of type 'double'. Error in material2 (line 83) overlapRatio = bboxOverlapRatio(expandedBBoxes, expandedBBoxes);

PLEASE!!!

I REALLY NEED HELP WITH THIS