Re: Re: Re: [ncl-talk] How to read a 3-d ascii grid data file ?

Hi,Thanks for your help. I do some test for my ncl code and get :

If I set the code as:
......
filName = "/home/linx/NCDC/GHCN/Grid/Grid_PRCP_1900-2005_Ascii.dat"
print(filName)
data = asciiread(filName,(/36*72*106,15/),"float") ; 36 lat grid,72 lon grid,106 years
printVarSummary(data) ; NCL can get the data value the give a output soon

nRow = numAsciiRow (filName) ; It seem that ncl can't get a nRow value
nCol = 15
print("nRow="+nRow) ; Ncl also give no output for nRow
.........

If I set the code directly as :

filName = "/home/linx/NCDC/GHCN/Grid/Grid_PRCP_1900-2005_Ascii.dat"
 Row = numAsciiRow (filName)
 nCol = 15
 print("nRow="+nRow)
 data = asciiread (filName, (/nRow,nCol/), "float")
 printVarSummary(data)

ncl can't read data and give no result

I wonder if the function of "numAsciiRow" can give a correct return for my ascii data file
and why ?

I'm sorry for sending mail directly to you. It's my fault . Next time I won't directly reply the received
mail. And thanks again for your mails.


Lin










LEO_ARIES
2006-05-19



·¢¼þÈË£º Dennis Shea
·¢ËÍʱ¼ä£º 2006-05-19 01:01:51
ÊÕ¼þÈË£º Leo_Aries_at_tom.com
³­ËÍ£º ncl-talk_at_ucar.edu
Ö÷Ì⣺ Re: Re: [ncl-talk] How to read a 3-d ascii grid data file ?

>Thanks for the reply. I have set my data as the format below:
>
>190001.0 87.50 -157.50 -327.68 -327.68 -327.68 -327.68 -327.68
-327.68 -327.68
>190001.0 87.50 -152.50 -327.68 -327.68 -327.68 -327.68 -327.68
-327.68 -327.68
>........
>the 1st column is yyyymm (float) and 2nd/3rd is lat/lon, the other right 12
colums is the value of Jan to Dec.
>
>I use the code below to read it,But still can't get the right result.
>(NCL use more than 95% of my xeon cpu£¬but fail to finish running£©
>
>
>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
>filName = "Grid_PRCP_1900-2005_Ascii.dat"
>nRow = numAsciiRow (filName)
>nCol = 15
>
>data = asciiread (filName, (/nRow,nCol/), "float")
>printVarSummary(data) ; It seem that ncl stop here because the
printVarSummary(data)
> didn't give a output
>
>yyyymm = floattointeger(data(:,0)) ; this convert float to integer
>
>lats = data(0:2591,1) ; 36*72=2592 grids
>lons = data(0:2591,2)
>PRCP = data(:,3:)
>
>PRCP!0 = 'lat'
>PRCP!1 = 'lon'
>PRCP!2 = 'time'
>PRCP_at_lat = lats
>PRCP_at_lon = lons
>PRCP_at_time = ? ;I also want to know how to set time property of
PRCP appropriately.
________________________________________



Well, first of all, PRCP is not a lat/lon grid.

It is PRCP(nROW,12) where the 12 represents months of the year.
I suggest that you use "printVarSummary" often to look
at an overall view of your variable.

The following is untested and should give you a start.


begin
 filName = "Grid_PRCP_1900-2005_Ascii.dat"
 nRow = numAsciiRow (filName)
 print("nRow="+nRow)
 nCol = 15

 data = asciiread (filName, (/nRow,nCol/), "float")
 printVarSummary(data) ; It seem that ncl stop here because the
                                                                                   didn't give a output


 DATA = data(:,3:) ; (nRow,12)

 yrStrt = 1900
 yrLast = 2005
 nyrs = yrLast-yrStrt+1
 nmos = 12

 ntim = nyrs*nmos
 time = new ( ntim, "integer")
 nt = 0
 do yr=yrStrt,yrLast
       time(nt:nt+nmos-1) = yr*100 + ispan(1,nmos,1)
       nt = nt+nmos
 end do
 time_at_long_name = "year_month"
 time_at_units = "yyyymm"
 time!0 = "time"
 time&time = time
 printVarSummary(time)

 nlat =
 mlon =

 latStrt = 87.5
 lonStrt = -157.5

 dlat = 2.5 ; ???
 dlon = 2.5

 lon = ispan(0,mlon-1)*dlon + lonStrt
 lon!0 = "lon"
 lon_at_long_name = "longitude"
 lon_at_units = "degrees_east"
 lon&lon = lon
 printVarSummary(lon)

   
 lat = ispan(0,mlon-1)*dlon + lonStrt
 lat!0 = "lon"
 lat_at_long_name = "latitude"
 lat_at_units = "degrees_north"
 lat&lat = lat
 printVarSummary(lat)

 PRCP = new ( (/ntim,nlat,mlon/), "float")
 PRCP!0 = "time"
 PRCP!1 = "lat"
 PRCP!2 = "lon"
 PRCP&lat = lat
 PRCP&lon = lon
 PRCP&time = time
 PRCP_at_long_name = "..."
 PRCP_at_units = "..."

 nt = 0
 do nr=0,nRow-1 ; loop over rows
       PRCP(nt:nt+11,:,:) = (/ DATA(nr,:) /) ; store 12 months of data
       nt = nt+12
 end do

 printVarSummary(PRCP)
 printMinMax(PRCP, True)

end

Please do not email me directly. I do see ncl-talk

_______________________________________________
ncl-talk mailing list
ncl-talk_at_ucar.edu
http://mailman.ucar.edu/mailman/listinfo/ncl-talk

_______________________________________________
ncl-talk mailing list
ncl-talk_at_ucar.edu
http://mailman.ucar.edu/mailman/listinfo/ncl-talk
Received on Thu May 18 2006 - 12:39:01 MDT