Re: How to read a 3-d ascii grid data file ?

Hi Lin,

Your ascii file is quite large. (That shouldn't be an issue though.) I
suspect something is slightly wrong with your ascii file. Did you try
creating an ascii file of just one timestep and try reading it into NCL?
Also, does NCL just hang, or does it return any kind of error message?
If it just hangs I suspect something is wrong with your ascii file.
Adam

LEO_ARIES wrote:
> 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
> ------------------------------------------------------------------------
> *发件人：* Dennis Shea
> *发送时间：* 2006-05-19 01:01:51
> *收件人：* Leo_Aries_at_tom.com
> *抄送：* ncl-talk_at_ucar.edu
> *主题：* 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

-- 
--------------------------------------------------------------
Adam Phillips			             asphilli_at_ucar.edu
National Center for Atmospheric Research   tel: (303) 497-1726
ESSL/CGD/CAS                               fax: (303) 497-1333
P.O. Box 3000				
Boulder, CO 80307-3000	  http://www.cgd.ucar.edu/cas/asphilli
_______________________________________________
ncl-talk mailing list
ncl-talk_at_ucar.edu
http://mailman.ucar.edu/mailman/listinfo/ncl-talk