You're trying to write the equivalent of
Z = [1 2 4; ...
3 ; ...
8 ; ...
9 ; ...
8 5 2];
Can't do that unless Z is a cell array containing two 3x1 and a 1x3 array.
You needs must write
x00 = [xyr(1,1,1) ; px.' ; xyr([1 1 1])] ;
or create px as a row vector instead of column to have a square array.
As said, not sure what you then intend to do with the result; from looking at the data values doesn't look to me quite like what line input array likely is needing to be, but this solves your concatenation problem first; can look at the result next.
