Re: [ferret_users] Plotting with a paleo time scale

["Ansley C. Manke" <ansley.b.manke@xxxxxxxx>]

I think you can get what you want with the  /VLIMITS qualifier on your SHADE command.  If you have a time axis defined with T=-1998:4001, then this will flip it so 4001 is at the bottom of the axis and -1998 at the top.  Simple example:

   yes?  DEFINE AXIS/T=-1998:4001:1/UNITS="Years BP"  taxis
   yes? define axis/x=0:359:1/units=degrees_east xaxis
   yes? let var = t[gt=taxis] + x[gx=xaxis]
   yes? shade/vlimits=4000:-1998 var

On 10/10/2018 2:35 AM, Olivier Marti wrote:

Hello,

I want to plot data using a paleo time scale : time is decreasing from a positive value to zero (present day).

The following script gives more details : 

USE "https://vesg.ipsl.upmc.fr/thredds/dodsC/store/p86mart/IPSLCM5A2/PROD/Holocene/TR5AS-Vlr01/ATM/Analyse/TS_YE/TR5AS-Vlr01_20000101_79991231_1Y_t2m.nc"

! Model Years are from 2000 to 7999, which correspond to nothing :-(

! I can define a time axis starting at 1, which it's less confusing

LET nt = `t2m_yearmean,RETURN=lsize`

DEFINE AXIS/T=1:`nt`:1/UNITS="Years" YearFromStart

! But the labelling I want is Year before present (present being 1850)

LET/TITLE="Years BP"   YearBP=6000-T[GT=YearFromStart]+1

! I can not define the following axis because it's reversed

!DEFINE AXIS/T/UNITS="Years"/NAME="YearBP" YearBP

LET t2m = t2m_yearmean[GT=YearFromStart@ASN]-273.15

! How can I use YearBP as an axis to have proper labelling 

! of the time axis on the following plot  ?

SHADE  t2m[Y=-2:2@AVE,L=1:5000@SBX:250] 

Any idea ?

Thanks,

Olivier

-- 

Dr. Olivier Marti  - mailto:olivier.marti@xxxxxxxxxxxx

Laboratoire des Sciences du Climat et de l'Environnement

Institut Pierre Simon Laplace

Laboratoire CEA-CNRS-UVSQ  -  UMR 8212

Tel : +33 1 69 08 77 27 - Mob : +33 6 45 36 43 74

Fax : +33 1 69 08 30 73

<http://www.lsce.ipsl.fr/Pisp/olivier.marti>