GridMethod-RegularSpace
To convert your worksheet data to matrix data using the Regular gridding method, your worksheet data must satisfy the following conditions:
To check for regularity, plot your X and Y data columns as a scatter graph and look for regular spacing in the X and Y dimensions. Note that in the following example (see the picture below), the data are regularly spaced in the X dimension and regularly spaced in the Y dimension and that the X and Y increments need not be equal.
If your data qualifies as regular data: