All values must be different. They are expressed in meters when working in longitude-latitude coordinates, or in the same units as in file.dat when working in plane coordinates. Since they are distance values, they have to be positive. Values are arranged in a succession of tables, each table with a number of lines equal to the number of distance classes and with a number of columns equal to the square of the number of variables. The last table has a number of lines and columns equal to the number of variables and corresponds to the covariance matrix.
Variances appear on the diagonal of the matrix, and covariances on either side of the diagonal.
The matrix is square and symmetric, and counts as many lines and columns as variables. It contains the same information as the .var file. Data are specially formatted and documented, in order to offer a more convenient presentation to the user. The data are contained in file example.dat . The file has no missing data.