% remove duplicate points
[uniqueZ,uniqueXY] = groupsummary(groundPoints(:,3),groundPoints(:,1:2), @mean);
Your first parameter groundPoints(:,3) is a numeric column vector (not a table() object), so you are using the "array data" form of groupsummary()
Your groupingvars input, groundPoints(:,1:2) is a matrix with two columns. The documentation says,
- For array input data, groupvars can be either a column vector with the same number of rows as A or a group of column vectors arranged in a matrix or cell array.
Notice the wording here implies that having the groupingvars have more than one column, is to be treated as having multiple column vectors. This will be important in a second.
You are using multiple outputs from groupsummary. The second one, BG, is documented as
For more than one input vector, BG is a cell array containing column vectors of equal length. Information for each group is contained in the elements of a row across all vectors in BG. Each group maps to the corresponding row of the output array B.
Remember a moment ago the wording for groupingvars indicated that if there is more than one column that it is treated as multiple column vectors; now take that wording into the description of BG and we see that "For more than one input vector, BG is a cell array" -- so multiple columns in groupvars will get you a cell array output.
I would suggest that you
[uniqueXY, ~, G] = uniquetol(groundPoints(:,1:2), 'rows');
uniqueZ = groupsummary(groundPoints(:,3), G, @mean);
