A method of storing in a memory digital data representing a topological network having a set of nodes (0-cells), segments (1-cells), and areas (2-cells) within concatenated 1-cells. For each 1-cell there are stored an associated first 0-cell and second 0-cell and also a thread pointer assigned to the 0-cells. The thread pointer of an 0-cell indicates the next-following 1-cell obtained by rotating the 1-cell in question in a predetermined direction of rotation around such 0-cell. For finding a 2-cell, use is made of a first 1-cell and the thread pointer associated with one of its 0-cells is followed after which, starting from the newly found 1-cell, each time the thread pointer of the opposite 0-cell is used until the first 1-cell is found again.