Re: [ferret_users] how to get Pressure(mb) axis data in reverse order

["Yogesh K. Tiwari" <ktiwari@xxxxxxxxxxxxxxx>]

Hello Ansley,

Thanks for your following suggestion but it 
did not work.

>  Compare what the plots look like, before doing any regridding:
>   set data q.nc; fill q[l=1,x=-170] ; cancel data q.nc
>   set data/order=-z q.nc; fill q[l=1,x=-170] ; cancel data q.nc
While step :-

set data/order=-z q.nc

fill q[l=1,x=-170]

The ferret complains :-
!++++++
**ERROR: illegal limits: Q is not in the 
range X=-170
Axis extremes are X=0.5:19.5
!+++++++++

This is because after the 'set data/order=-z' 
command the x-axis and z-axis dimensions are 
interchanged between each other, as:-

yes? sh dat
currently SET data sets:
1> ./q.nc  (default)
name  title   I     J       K      L
 Q           1:19  1:73   1:97   1:12


Whereas the real data and its axis dimensions 
are like :-

!++++++++++++++++++++++++
yes? sh dat
currently SET data sets:
1> ./q.nc  (default)
name  title  I     J     K      L
 Q          1:97  1:73  1:19   1:12
!++++++++++++++++++++++++

for me its very starnge , why the x-axis and 
z-axis intercganged after saying /order=-z.

Also when I say :-

yes? cancel data q.nc
 **ERROR: unknown data set: q.nc

Why this error whereas data is there in the 
same dir and 'set data q.nc' works.

For this problem I had to check the
/order = -z command in two separate ferret 
sessions.

!++++++++++++++++
!++++++++++++++++++++

Now yours second suggestion :-

>  set data/order=-z q.nc
>  let press = {0.0, 7.76, ...}
>  def axis/depth/z/units=mb zpressure = press
>   let q2=q[gz=zpressure@ASN]

fill q2[l=1,x=-170]


Did not work.

ferret complains :-
!+++++++++++++++++
fill/nolab/vlimits=0:1000:100/lev=(373,383,.5)\ 
q2[l=3:5@ave,x=-170]+355.7645

 **ERROR: illegal limits: M2 is not in the 
range X=-170
          Axis extremes are X=0.5:19.5
CONTOUR/FILL/nolab/vlimits=0:1000:100/lev=(373,383,.5) 
m2[l=3:5@ave,x=-170]+355.7645
Command file, command group, or REPEAT 
execution aborted
!+++++++++++++++++


Because the x-axis and z-axix dimensions 
interchanged.


yes? sh dat
currently SET data sets:
1> ./q.nc  (default)
name  title   I     J       K      L
 Q           1:19  1:73   1:97   1:12


Kindly help,

Regards,
Yogesh




>  
> Yogesh K. Tiwari wrote:
>
> > Hello Ferret Users,
> >
> > I want to change sigma level z-axis with pressure(mb) values so I 
> > wrote a script.
> >
> > !++++++++++++++++++++
> >
> > set data q.nc
> >
> > let press =\
> >   {0.0,7.76486715808502,19.1474920954818,\
> > 5.5095334329671,57.7252298204432,86.0958233667092,\
> > 120.320114961464,159.597308168984,205.375139312848,\
> > 269.693181583253,363.907443320277,480.335709752363,\
> > 600.936070971621,710.819107916518,802.135476614033,\
> > 872.668797870758,923.727954421369,958.711821388422,\
> > 982.300930711410,999.956798673119}
> >
> > define axis/z/units=mb zpressure=press
> >
> > let q2=q[gz=zpressure@ASN]
> >
> > fill m2[l=1,x=-170]
> > !++++++++++++++++++++++
> >
> > The defined 'press' values are monotonic increasing order. Monotonic 
> > decreasing order definition not working.
> >
> > Here the fill plot which I get has the y-axis in reverse order, means, 
> > 0 in lower and 1000 mb in upper part of axis range.
> >
> > I tried to change the order of defined pressure values 'press', I kept 
> > it in monotonic decreasing order but ferret complains .....**NOT A 
> > monotonic order.
> >
> > I tried to keep 'DEPTH' qualifier but problem did not solved and tried 
> > 'vlimits' to reverse it but the whole map reverses with the reversing  
> > y-axis pressure values.
> >
> > Can any body help, how to reverse only the pressure values on y-axis, 
> > or if any thing wrong in my script.
> >
> > Many thanks for your help.
> >
> > Regards,
> > Yogesh

--

===========================================
Yogesh Tiwari,
Max-Planck Institute for Biogeochemistry,
Hans-Knoell Strasse 10,
D-07745 Jena,
Germany

Office   : 0049 3641 576 376
Home     : 0049 3641 223 163
Fax      : 0049 3641 577 300
Cell     : 0049 1520 4591 008
e-mail   : yogesh.tiwari@bgc-jena.mpg.de
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