This function has been used 1990 times.
Source data must be in columns as: [X] [Y] [value] (each case in a separate row, column separator can be space,
tab or semicolon, decimal separator can be either point or comma). Lines beginning with a character (field names) are excluded.
Moran's I quotient is calculated locally at grid interval specified by the user using data located within given radius around the grid nodes.