RE: Negative longitudes

["McCann, Mike" <mccann@xxxxxxxxx>]

This is to close the question for the mail archives-

Steve provided the answer I needed for renaming my single
point negative longitude axis and making it positive.

To recap, I wanted to change the name of the X & Y axes.
Defining the edges and adding 360 to longitude works for
my data:

LET FOO = x[gx=ADCP_LONGITUDE]  ! Scalar for below
LET BAR = y[gy=ADCP_LATITUDE]   ! Scalar for below
DEFINE AXIS/Y/EDGES/UNITS=deg LATITUDE={`BAR-0.5`,`BAR+0.5`}
DEFINE AXIS/X/EDGES/UNITS=deg LONGITUDE={`FOO+360-0.5`,`FOO+360+0.5`}


-Mike

> -----Original Message-----
> From: McCann, Mike 
> Sent: Tuesday, May 29, 2001 4:14 PM
> To: 'Steve Hankin'
> Cc: ferret_users@ferret.wrc.noaa.gov
> Subject: RE: Negative longitudes
> 
> 
> Steve,
> 
> Thanks for the answer.  I need to have the axis modulo, otherwise
> the data set does not work in LAS.  I think my best avenue for now,
> until 5.3 is available, is to add 360 to my longitude axes.  What 
> is the best way to do this dynamically inside a GO script?   
> 
> -Mike 
> 
> > -----Original Message-----
> > From: Steve Hankin [mailto:hankin@pmel.noaa.gov]
> > Sent: Tuesday, May 29, 2001 3:16 PM
> > To: McCann, Mike
> > Cc: ferret_users@ferret.wrc.noaa.gov
> > Subject: Re: Negative longitudes
> > 
> > 
> > Hi Mike,
> > 
> > The problem that you report is due to a bug in V5.22.  It has 
> > been fixed in
> > V5.3.
> > 
> > As a work-around for the problem in V5.22 try this:
> >    yes? def axis/x/units=deg/edges x1={-123,-122}
> > 
> > You can peek into the internals of the bug by noting the 
> > erroneous output of
> > SHOW AXIS/X (see the messed up "BOX_SIZE":
> > 
> >  yes? def axis/x/units=deg/modulo x1={-122.5}
> >  yes? show axis/x x1
> >   name       axis       # pts   start                end
> >   X1        LONGITUDE     1mr   122.5W(-122.5)    122.5W(-122.5)
> >            I     X                 BOX_SIZE
> >            1>  122.5W(-122.5)        -61.25
> > 
> >     - steve
> > 
> > -------
> > 
> > P.S. Do you really want "/modulo" for a single point axis? If 
> > so, then you
> > probably would want to make sure the axis span is 360 degrees as in
> >  yes? def axis/x/units=deg/edg/mod x1={`-122.5-180`,`-122.5+180`}
> >  yes? show axis/i=1:3 x1
> >   name       axis      # pts   start            end
> >   X1        LONGITUDE    1mi   122.5W(-122.5)   122.5W(-122.5)
> > 
> >            I     X                 BOX_SIZE
> >            1>  122.5W(-122.5)        360
> >            2>  122.5W                360
> >            3>  122.5W(597.5)         360
> > 
> > =======================================================
> > 
> > "McCann, Mike" wrote:
> > 
> > > Hi Ferreters,
> > >
> > > I'm trying to rename an axis and have encountered a strange thing
> > > that can be boiled down to this little example:
> > >
> > >   def axis/x/units=deg/modulo x1={-122.5}               ! 
> > Negative Long
> > >   let v1=x[gx=x1]
> > >   def axis/x/units=deg/modulo/name=x2 v1
> > >
> > > gives the error:
> > >
> > >   **ERROR: illegal limits: V1 is not in the range X=122.5W(-122.5)
> > >           Axis extremes are X=122.5W(-122.5)
> > >
> > > whereas
> > >
> > >   def axis/x/units=deg/modulo x1={122.5}                ! 
> > Positive Long
> > >   let v1=x[gx=x1]
> > >   def axis/x/units=deg/modulo/name=x2 v1
> > >
> > > gives no error.
> > >
> > > I've read
> > > 
> http://ferret.wrc.noaa.gov/Ferret/Mail_Archives/fu_97/msg00031.html
> > > but would prefer not having to add 360 to my longitudes.
> > >
> > > Is the above example normal behavior?  Is there a simpler way to
> > > give an axis a new name?
> > >
> > > Thanks in advance,
> > > Mike
> > >
> > > --
> > > Mike McCann   (mccann@mbari.org)
> > > Monterey Bay Aquarium Research Institute
> > > 7700 Sandholdt Road
> > > Moss Landing, CA 95039-9644
> > > Voice: (831) 775-1769   Fax: (831) 775-1646 
> > http://www.mbari.org/rd/iag.htm
> > 
> > --
> > 
> >                 |  NOAA/PMEL               |  ph. (206) 526-6080
> > Steve Hankin    |  7600 Sand Point Way NE  |  FAX (206) 526-6744
> >                 |  Seattle, WA 98115-0070  |  hankin@pmel.noaa.gov
> > 
> > 
>