Thank you Ansley and Akshay, I could able to plot from your script but
I didn't understand about radius and cutoff, please anyone explain
about these two, and what this function exactly does, whether 0.1
interval is necessary in define axis field ?
awaiting for answer
- Dona Clara
------------------------------------------------------------------------
*From:* Akshay Hegde <akshay.k.hegde@xxxxxxxxx>
*To:* Don DNA <don_vbe@xxxxxxxxx>
*Cc:* Ansley Manke <ansley.b.manke@xxxxxxxx>; "ferret_users@xxxxxxxx"
<ferret_users@xxxxxxxx>
*Sent:* Saturday, June 1, 2013 6:24 PM
*Subject:* Re: [ferret_users] Reading text file and creating netcdf
file by using define axis from variable
Hi Dona as Ansley sir suggested you could use scat2gridgauss_xy
function for more detail go through
http://ferret.pmel.noaa.gov/Ferret/documentation/users-guide/appendix-a-external-functions/scat2grid_nobs_xy/
for usage of function and to save variable as netcdf have a look on
sample script I just played little bit with your data,other may give
better solution to you
copy below script and save as jnl file
just run on terminal
go filename.jnl
! Memory setting it depends on your system
set mem/size=800
! Define axis here
define axis/x=40:100:0.1/units=longitudes xlon
define axis/y=0:25:0.1/units=latitudes ylat
! Define Grid
define grid/x=xlon/y=ylat fun
! Read File Here....
file/skip=1/grid=fun/var="lat,lon,grd" Data.txt
! Regrid your variable into the grid fun
let Grad_1 = grd[g=fun@asn]
! Define limits here for scat2grid function
! Play with radius and cuttoff
define symbol radius = 1
define symbol cutoff = 4.0
let lon_1D = XSEQUENCE(lon)
let lat_1D = XSEQUENCE(lat)
let Grad_1D = XSEQUENCE(Grad_1)
!************************************************************************************************************************
! Call scat2gridgauss_xy function
! for more detail go through
http://ferret.pmel.noaa.gov/Ferret/documentation/users-guide/appendix-a-external-functions/scat2grid_nobs_xy/
!************************************************************************************************************************
let Grad_2 = scat2gridgauss_xy(lon_1D,lat_1D,Grad_1D,\
x[gx=fun],y[gy=fun],($radius),($radius),($cutoff),($cutoff))
! If required then set title and units
set var/title="My title "/units="my units" Grad_2
! Have a look on grid
sh grid Grad_2
contour/fill/key/line/lev=(0,4,0.25) grad_2
go fland 20
go land thick
! For saving use either save
save/file=myfile_1.nc/clobber <http://myfile_1.nc/clobber> grad_2
! OR list
list/file=myfile_2.nc/clobber <http://myfile_2.nc/clobber> grad_2
frame/file=test.gif
Akshay Hegde,
National Institue of Oceanography
Dona Paula, Goa
On Sat, Jun 1, 2013 at 12:12 PM, Don DNA <don_vbe@xxxxxxxxx
<mailto:don_vbe@xxxxxxxxx>> wrote:
Yes, Ansley what you said is right, points are scattered, but I
don't understand scat2grid function usage, and how much accurate
it is, which interpolation I need to use, is there any functions
for interpolation ? In fact right now I am completely depending on
forum
- Dona Clara
------------------------------------------------------------------------
*From:* Ansley Manke <ansley.b.manke@xxxxxxxx
<mailto:ansley.b.manke@xxxxxxxx>>
*To:* Don DNA <don_vbe@xxxxxxxxx <mailto:don_vbe@xxxxxxxxx>>
*Cc:* "ferret_users@xxxxxxxx <mailto:ferret_users@xxxxxxxx>"
<ferret_users@xxxxxxxx <mailto:ferret_users@xxxxxxxx>>
*Sent:* Friday, May 31, 2013 10:13 PM
*Subject:* Re: [ferret_users] Reading text file and creating
netcdf file by using define axis from variable
Hi Don,
Defining an axis directly from the data only makes sense if the
data is actually organized as a grid.
Your data looks like it's at a set of scattered points. Is that
the case? To check what the distribution of the points looks like,
you can plot them as marks on a map
yes? file/skip=1/var="lat,lon,grd" Data.txt
yes? go basemap
yes? plot/vs lon, lat
If the points are scattered, you could use one of the SCAT2GRID
functions. Define a grid, and call the function to interpolate
the variable GRD onto the grid.
--Ansley
On 5/31/2013 6:44 AM, Don DNA wrote:
Please anyone help me, I am having text file, I could able to
read it using following command
yes? file/skip=1/var="lat,lon,grd" Data.txt
yes? sh d
currently SET data sets:
1> ./Data.txt (default)
name title I J K L M N
LAT LAT 1:20480 ... ... ... ... ...
LON LON 1:20480 ... ... ... ... ...
GRD GRD 1:20480 ... ... ... ... ...
list /i=1:10 lat,lon,grd
DATA SET: ./Data.txt
X: 0.5 to 10.5
Column 1: LAT
Column 2: LON
Column 3: GRD
LAT LON GRD
1 / 1: 11.83 88.93 0.3000
2 / 2: 11.95 87.95 0.1000
3 / 3: 12.10 86.98 0.3000
4 / 4: 17.67 40.43 0.3000
5 / 5: 24.82 57.92 0.3000
6 / 6: 13.28 42.93 0.0500
7 / 7: 7.93 73.32 0.1800
8 / 8: 7.25 72.00 0.2400
9 / 9: 4.33 67.43 0.0600
10 / 10: 24.07 57.59 0.0200
define axis/X/units=Degrees_East xaxis=lon[i=1:2791]
**ERROR: improper grid or axis definition: data for DEFINE
AXIS/FROM_VARIABLE is not monotonic at index 2
define axis/Y/units=Degrees_north yaxis=lat[i=1:2791]
**ERROR: improper grid or axis definition: data for DEFINE
AXIS/FROM_VARIABLE is not monotonic at index 6
Now I want to create netcdf file, I searched in user list and in
ferret website, in that I found that axis can be defined by using
variable, but in my case I am unable to define axis from
variable, I don't have much idea about ferret programming, please
those who know kindly help me, and please go through attachment.
- Dona Clara.