Source data must be in columns as: [ID] [X] [Y] or as [ID] [X] [Y] [Code] if the nearest neighbour has to be found only within the same group. Grouping codes can be either characters or numbers. ID must be a short integer. Each object in a separate row, column separator can be either space, tab or semicolon, decimal separator can be either point or comma. Lines beginning with a character (headings) are removed.