In the SOPALE code, the Eulerian grid is considered to be "grid 1" and the Lagrangian grid is "grid 2". Knowing this convention can help decipher some variable names and filenames; for example, the array x1 contains the x coordinates for the Eulerian grid, and the array x2 contains the x coordinates for the Lagrangian grid. The output files containing model results for the Eulerian grid have names starting with "g01", and the output files containing model results for the Lagrangian grid have names starting with "g02".
In SOPALE, the nodes of a grid are numbered starting at the upper left corner of the grid and moving down each column.
The elements (or cells) of a grid are numbered starting at the upper left element and moving across each row.
