[ferret_users] Solid contours for negative values? Thin zero contours?

[Ryo Furue <furue@xxxxxxxxxx>]

Hi Ferret users,

I guess I'm missing something, but could somebody tell me
how to control the "dash-ness" and thickness of contours?

In particular,
1) How to draw solid contours for negative values?
2) How to draw thin contours for the value zero?

I've found that setting the spacln parameter of CONSET
to zero achieves (1):

   yes? contour/set . . .
   yes? ppl conset ,,,,,0  !!<-- spacln = 0
   yes? ppl contour

But is this an "official" answer?

(2) is very sensitive to how you set contour levels.
For example, "lev=1CD" gives thick zero contours,
whereas "lev=(-5,5,1,-1)" sometimes gives thin ones
and sometimes thick ones, which seems to depend on history.
In addition, I've discovered an undocumented keyword BLAH
 
       . . . /lev=(-10,10,1,-1)BLAH(-10,10,1)

which always gives thin zero contours :-)
(This is true, but don't believe that it's a keyword.)

I'm using FERRET v5.81, Linux(g77) 2.4.21-32 - 07/13/05.

Thank you,
Ryo