Re: gsn_csm_vector Vs gsn_vector

Hi Sabeer,

I suspect that your problem is the same as another user (Cheung) had recently. First of all, as Mary Haley pointed out:

The main difference between gsn_vector and gsn_csm_vector is that gsn_vector doesn't use coordinate arrays that may be attached to your data.
This is part of the cause in difference of your two plots.

The other thing is my response to Cheung:

By default, the vector direction is mapped into the coordinate space defined by the coordinate variables. This is appropriate for horizontal vectors drawn on a map, but not for vectors in a vertical space such as yours where the Y axis and the X Axis have completely unrelated units. To fix this you should set the resource vcMapDirection to False. This will make the output of gsn_vector and
gsn_csm_vector look pretty much alike. However, it also has the effect of always making the positive Y direction from bottom to top. If, as you say, the gsn_vector output looks like what you want, it may mean the vertical component is positive from top to bottom of the atmosphere. If this is the case, then you will need to multiply the vertical component by -1.0 to get the result you are looking for.

----
So bottom line is: set vcMapDirection to False.
 -dave
On May 26, 2011, at 6:11 AM, Sabeerali(sebi) wrote:
> Dear Mateus,
> 
> Thanks for your response. As you said there are some difference between graphics generated with  gsn_* functions and those generated with gsn_csm* functions. But when we plot with gsn_csm_vector functions, the Hadley circulation never comes to reality. It gives entirely wrong picture ( It never gives the ascending and descending motion. It gives some horizontal vectors). But when we plot with gsn_vector functions, it gives correct plot. But the problem with the gsn_vector function is that it never gives the coordinate in X and Y axis. In that case how I can resolve my issues.
> 
> Thanks in advance
> sabeer
> 
> 
> On 26 May 2011 16:53, Mateus Teixeira <mateus.teixeira@gmail.com> wrote:
> Hi Sabeerali,
> 
> As you can see in the section 2.2 of the graphics manual (http://www.ncl.ucar.edu/Document/Manuals/) there are some changes between graphics generated with gsn_* functions and those generated with gsn_csm* functions.
> 
> Please, take a look in that sections of the graphics manual.
> 
> Best regards,
> 
> Mateus
> 
> 
> 
> 
> 2011/5/26 Sabeerali(sebi) <sabeerl@gmail.com>
> Dear NCL users,
> 
> I used the function  "gsn_vector" to plot the jjas mean Hadley circulation and I got the correct plot. But to have more control over the plot ( I have to get coordinate in X and Y), i used the  "gsn_csm_vector" function. But in this case I getting a different plot. Why this difference is coming and what is the solution? In the following script I changed only gsn_vector to gsn_csm_vector.Any help would be greatly appreciated.
> 
> I used the ncep v wind and omega. For scaling I multiplied the omega with -100
> 
> Thanks in advance
> sabeer
> 
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
> begin
> wf=addfile("mon.omega.nc","r")
> vf=addfile("mon.vwnd.nc","r")
> 
> date=ut_calendar((wf->time),-5)
> month=date(:,1)
> jjas_indx=ind(month.eq.06.or.month.eq.07.or.month.eq.08.or.month.eq.09)
> 
> w=short2flt(wf->omega(jjas_indx,:,::-1,{68:80}))
> v=short2flt(vf->vwnd(jjas_indx,:,::-1,{68:80}))
> 
> jjas_w=dim_avg_n_Wrap(w(:,:,{-30:30},:),0)
> jjas_v=dim_avg_n_Wrap(v(:,:,{-30:30},:),0)
> 
> jjas_w_lonavg=dim_avg_n_Wrap(jjas_w,2)
> jjas_v_lonavg=dim_avg_n_Wrap(jjas_v,2)
> 
> ws=jjas_w_lonavg*-100
> copy_VarCoords(jjas_w_lonavg,ws)
> 
> wks=gsn_open_wks("x11","hadley")
> gsn_define_colormap(wks,"gui_default")
> res  = True
> res@tiMainString          = ""
> res@gsnSpreadColors       = True
> res@vcRefMagnitudeF       = 7.0
> res@vcRefLengthF          = 0.045
> res@vcMonoLineArrowColor  = False
> res@vcGlyphStyle          = "CurlyVector"
> 
> ;;plot = gsn_vector(wks,jjas_v_lonavg,ws,res)
> 
>  plot=gsn_csm_vector(wks,jjas_v_lonavg,ws,res)
> 
> end
> 
> _______________________________________________
> ncl-talk mailing list
> List instructions, subscriber options, unsubscribe:
> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
> 
> 
> 
> 
> -- 
> Mateus da Silva Teixeira
> Registered Linux User #466740 (http://counter.li.org/)
> 
> 
> _______________________________________________
> ncl-talk mailing list
> List instructions, subscriber options, unsubscribe:
> http://mailman.ucar.edu/mailman/listinfo/ncl-talk

_______________________________________________
ncl-talk mailing list
List instructions, subscriber options, unsubscribe:
http://mailman.ucar.edu/mailman/listinfo/ncl-talk
Received on Thu May 26 11:14:17 2011