#3 Missing casename throws exception

[Daryl Lee]

I ran the Pontius dataset, and tried to map it to a
linear model (y = C0 + C1*x). C0 and C1 mapped to
constants okay, but I could not map x and y because
case names are missing. When I selected (col 0) and x
and then clicked Link, Pascal threw an 'index out of
range (-1)' error.