[ferret_users] FILE/ command works only when executed twice

[Hella Riede <hella.riede@xxxxxxx>]

Dear ferreters,

I am reading ASCII data from a file ($tmpname) using the command

FILE/FORMAT=delim/DELIMITER=" "/grid=gbin/var="iweight" "($tmpname)"

The grid "gbin" spans a section in time, longitude, and latitude.
In some cases with a higher number of values to be read in (i.e. gbin 
has a higher resolution in longitude and latitude, for example 3x3 
degress instead of 10x10 degrees), the values of the variable iweight 
are all set to 1.356E-19, some machine phantasy number, I guess.

When I simply repeat the command as given above in the same shell, the 
values are all fine. Also, when I quit ferret and open it again, 
generate the grid and read the ($tmpname), the iweight values are fine. 
(Issuing the command "load iweight" after FILE/... by the way does not 
change anything.)

Now, I don't know enough about ferret's guts and my full example is 
longish and as mentioned above, only reading from the tmp file free from 
other script context works. The workaround, issuing the FILE/... command 
twice seems to do the job, but I have no idea how reliable that 
workaround is.

Has anyone encountered a similar behavior in ferret? Any ideas about 
file scan behavior, temporary storage, internal variables ...?

Cheers,
Hella