Re: Problems about ferret command "set axis/modulo "

[Olivier ARCHER <olivier.archer@xxxxxxxxxx>]

Chi wrote:
> Hi Jonathan and everyone
>   I found a problem with ferret command "set axis/modulo". I have a 3D 
> netcdf file,
> the longitude are west and are defined as    longitude = -30, -29.5, 
> -29, -28.5, -28, -27.5, -27;
>   If I don't use "set axis/modulo" command, just set region using
> set region/x="-27.5"/y="6.5":"11"/z="-200":"-1"/l=1, then everything is 
> fine
>   However, I found that the LAS generated ferret script called set 
> axis/modulo to setup longitude as modulo, then it used set 
> region/x="332.5"/y="6.5":"11"/z="-200":"-1"/l=1, but it didn't return the
> correct data/image at the longitude -27.5, which is what I needed.
>   I remembered that some perl source code of LAS said that since ferret 
> won't process
> negative west longitude well, then LAS automatically convert it to 
> positive east-wise
> value. However when I manually called ferret script to process my data 
> using negative west longitude, everything was fine. It was the "set 
> axis/modulo" command who caused me problems.
>   Anybody can help me about this? Or How can I configure LAS not to use 
> "sex axis/modulo"?
>   Thanks a lot, Ding
>  

Hi Chi,
	We've got there the same prolem, and "set axis/modulo" is called  from 
las/server/Ferret.pl



#grep -n -A 3 "set axis/modulo" Ferret.pl
583:        my $comm = "set axis/modulo `" . $var .
584-        "[d=" . $dexpr . "],return=xaxis`";
585-#        $self->command($comm);
586-      }

so I've commented $self->command($comm);
But what are side effect ? there is probably a better way to do.

--
Olivier