Ginput point in matrices

I have a matrices and a data point from ginput. I'm trying to find the corresponding point in my matrices to my data point, but the data point isn't exactly equal to any point in the matrices. For example my data point is 32.6025 but the closest data points are 32.6020 and 32.6027. How can I have matlab choose the matrices point that is closest to this ginput point?