Nav inaccurate with odd shaped curves

[tferr]

With profiles that are highly skewed or contain plateaus, Nav is not accurate (v3.4.4). The following macro demonstrates this:

run("ddaC Neuron (84K)");
run("Sholl Analysis...", "starting=200 ending=300 radius_step=0 fit linear polynomial=[8th degree]");

Retrieved: Nav = -139230.813. Expected: ~ 58.315