From: Dennis Shea <shea_at_nyahnyahspammersnyahnyah>

Date: Thu Oct 06 2011 - 14:35:22 MDT

Date: Thu Oct 06 2011 - 14:35:22 MDT

[1]=== Use coordinate subscripting

lat1 = -90

lat2 = 90

lon1 = -180

lon2 = 180

nyskip= 20

nxskip= 20

elv = f->z({lat1:lat2:nyskip},{lon1:lon2:nxskip})

printVarSummary(elv)

[2]=== Use 'ind' and avoid looping

lat = f->lat

lon = f->lon

j1 = ind(lat.eq.lat1)

i1 = ind(lon.eq.lon1)

j2 = ind(lat.eq.lat2)

i2 = ind(lon.eq.lon2)

elv = f->z(j1:j2:nyskip,i1:i2:nxskip)

printVarSummary(elv)

+++++++++++++++++++++++++++++++

lat = z&lat

lon = z&lon

nlat = dimsizes(z&lat)

nlon = dimsizes(z&lon)

resm@mpMinLonF = min(lon(0))

resm@mpMaxLonF = max(lon(nlon-1))

resm@mpMinLatF = min(lat(0))

resm@mpMaxLatF = max(lat(nlat-1))

++++++++++++++++++++

Elvation ==> Elevation

++++++++++++++++++++

Do not use (:,:), it is less efficient

Yes: plot_t =gsn_csm_contour(wks,elv,rest)

No: plot_t =gsn_csm_contour(wks,elv(:,:),rest)

+++++++++++++

If you are doing a cylindrical equidistant plot, we recommens

gsn_csm_contour_map_ce

On 10/6/11 2:15 PM, Adam Phillips wrote:

*> Hi Ahmed,
*

*> There are two ways to subscript: by using coordinate values, or by using
*

*> index values. I believe you are confusing the two methods here.
*

*>
*

*> Coordinate subscripting uses { } to denote that you are specifying
*

*> coordinate values (latitude/longitude values in your case)
*

*>
*

*> elv = f->z({j1:j2:20},{i1:i2:20})
*

*> elv = f->z({j1:j2},{i1:i2})
*

*> elv = f->z({j1:},{:i2})
*

*>
*

*> Index subscripting doe not:
*

*> elv = f->z(0:100:10,5:125:5})
*

*> elv = f->z(::10,::5})
*

*> elv = f->z(5::10,5::5})
*

*>
*

*> Note that in either case, the specified stride value must be an integer..
*

*>
*

*> In your case, I think you want this:
*

*> elv = f->z({j1:j2:20},{i1:i2:20})
*

*>
*

*> Hope that helps..
*

*> Adam
*

*>
*

*> On 10/06/2011 02:04 PM, ahmed lasheen wrote:
*

*>> Hello all
*

*>> I am trying to read and plot elevation data in which it's resolution is
*

*>> 5 minute , and when i plot it keeping in mind maximizing the workstation
*

*>> size and increasing the cnLevelSpacingF .
*

*>> when i use the com elv = f->z(::20,::20) , then it works well but when
*

*>> i use the command elv = f->z(j1:j2:20,i1:i2:20) where j1 is the first
*

*>> lat ,j2 is the second lat , i1 is the first lon and i2 is the second lon
*

*>> , then the image produces is wrong .anybody know why , i
*

*>> have attached the scripts.
*

*>> thanks
*

*>>
*

*>> --
*

*>> ===============
*

*>> Ahmed Lasheen
*

*>> Junior researcher at Cairo Numerical Weather Prediction Center (CNWPC)
*

*>> Egyptian Meteorological Authority(EMA)
*

*>> Cairo,Egypt
*

*>> ===============
*

*>>
*

*>>
*

*>>
*

*>> _______________________________________________
*

*>> ncl-talk mailing list
*

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*

*>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
*

*>
*

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Received on Thu Oct 6 14:35:29 2011

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