public static void plotFunction(Mesh mesh, Function fun, String fileName) {
NodeList list = mesh.getNodeList();
int nNode = list.size();
Variable var = new Variable();
Vector v = new SparseVectorHashMap(nNode);
for (int i = 1; i <= nNode; i++) {
Node node = list.at(i);
var.setIndex(node.globalIndex);
var.set("x", node.coord(1));
var.set("y", node.coord(2));
v.set(i, fun.value(var));
}
plotVector(mesh, v, fileName);
}
