Re: Is there a bug with fbinrecwrite or fbinrecread

Hi Guangshan,

Curiously, I get the following output, which appears to be correct:

(0)
(0) Monthly Longterm Mean of U-Wind: min=-37.2069 max=95.8738
(0)
(0) Monthly Longterm Mean of V-Wind: min=-33.7934 max=32.8907
(0) u-wind Min and Max values read from ./wind.mon.ltm.bin
(0)
(0) min=-37.2069 max=95.8738
(0) v-wind Min and Max values read from ./wind.mon.ltm.bin
(0)
(0) min=-33.7934 max=32.8907
(0) u-wind Min and Max values read from ./uwind.mon.ltm.bin
(0)
(0) min=-37.2069 max=95.8738

I hate to think there might be platform differences, but not sure what
to suggest here.
This was running NCL 5.1.1 under MacOS 10.5.8.

Rick

On Thu, 29 Oct 2009 21:19:20 -0500
  guangshan chen <gchen9@gmail.com> wrote:
> Dear all:
>
> It seems there is bug in fbinrecwrite or fbinrecread.
>
> Here is the test main idea:
> step 1: read netcdf file and get two variables data
> step 2: printMinMax values of variables
> step 3: using fbinrecwrite to write binary file
> step 4: using fbinrecread to read binary file
> step 5: printMinMax values of the new two variables
>
> But I compared the Min and Max values between the original data and
>
> new data read from binary file are different.
>
> Original Min and Max values:
> Monthly Longterm Mean of U-Wind: min=-37.2069 max=95.8738
> Monthly Longterm Mean of V-Wind: min=-33.7934 max=32.8907
>
> New Min and Max values read from binary file
> u-wind Min and Max values read from ./wind.mon.ltm.bin are
> min=-37.2069 max=81.1241
> v-wind Min and Max values read from ./wind.mon.ltm.bin are
> min=-36.9928 max=95.8738
>
> Also in my script I output only variable to binary file and read it,
>
> there is no problem.
> u-wind Min and Max values read from ./uwind.mon.ltm.bin are
> min=-37.2069 max=95.8738
>
> So Could anyone check what is going when outputting two variables?
>
> Thanks
>
> Guangshan
>
>
> ;================================================;
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/shea_util.ncl"
> ;================================================;
> ;load external functions should be included path;
> ;external function_name "./function_name.so"
> ;================================================;
> begin
> ;================================================;
> ;The binary file will be the same as a one open via fortran's open
> statement:
> ;
> ; open(..., form="unformatted", [,access="sequential"] ) ;
> sequential is default
>
> uwind_file = addfile("uwnd.mon.ltm.nc","r")
> vwind_file = addfile("vwnd.mon.ltm.nc","r")
>
> ; data can be download from
> ;http://www.esrl.noaa.gov/psd/cgi-bin/db_search/DBSearch.pl?Variable=U-
> ; Wind&Dataset=CDC+Derived+NCEP+Reanalysis+Products+Pressure+Level
> ;
>http://www.esrl.noaa.gov/psd/cgi-bin/db_search/DBSearch.pl?Variable=V-
> ; Wind&Dataset=CDC+Derived+NCEP+Reanalysis+Products+Pressure+Level
>
> lat = uwind_file->lat(::-1)
> print(lat)
> lon = uwind_file->lon
> lev = uwind_file->level
> time = uwind_file->time
>
> nlat = dimsizes(lat)
> nlon = dimsizes(lon)
> nlev = dimsizes(lev)
> ntime = dimsizes(time)
>
> ; make sure lat from -90. 90.
> uwind = uwind_file->uwnd(:,:,::-1,:)
> vwind = vwind_file->vwnd(:,:,::-1,:)
>
> printMinMax(uwind,True)
> printMinMax(vwind,True)
>
>
> setfileoption("bin","WriteByteOrder","BigEndian")
>
> path = "./wind.mon.ltm.bin"
>
> do itime=0,ntime-1
>
> do ilev=0,nlev-1
> fbinrecwrite(path,-1,(/uwind(itime,ilev,:,:)/))
> end do
>
> do ilev=0,nlev-1
> fbinrecwrite(path,-1,(/vwind(itime,ilev,:,:)/))
> end do
>
> end do
>
> ;************************************************************
> ; note the -1 indicates to just add on to the end of the file
> ; the (/.../) syntax means output the values only with no meta
> ; data
> ;************************************************************
>
> path1 = "./uwind.mon.ltm.bin"
>
> do itime=0,ntime-1
> do ilev=0,nlev-1
> fbinrecwrite(path1,-1,(/uwind(itime,ilev,:,:)/))
> end do
> end do
>
> ; read uwind and vwind binary file
>
> setfileoption("bin","ReadByteOrder","BigEndian")
>
> rec_dims=(/nlat,nlon/)
> rec_type="float"
>
> uwnd=new( (/ntime,nlev,nlat,nlon/), rec_type )
> vwnd=new( (/ntime,nlev,nlat,nlon/), rec_type )
> rec_num = 0
> do it=0,ntime-1
> do il=0,nlev-1
> uwnd(it,il,:,:)=fbinrecread(path,rec_num,rec_dims,rec_type )
> rec_num=rec_num+1
> end do
>
> do il=0,nlev-1
> vwnd(it,il,:,:)=fbinrecread(path,rec_num,rec_dims,rec_type )
> rec_num=rec_num+1
> end do
>
> end do
>
> print("u-wind Min and Max values read from "+ path)
> printMinMax(uwnd,True)
> print("v-wind Min and Max values read from "+ path)
> printMinMax(vwnd,True)
>
> ; read uwind only binary file
> uwnd_o=new( (/ntime,nlev,nlat,nlon/), rec_type )
> rec_num = 0
> do it=0,ntime-1
>
> do il=0,nlev-1
> uwnd_o(it,il,:,:)=fbinrecread(path1,rec_num,rec_dims,rec_type
>)
> rec_num=rec_num+1
> end do
>
> end do
>
> print("u-wind Min and Max values read from "+ path1)
> printMinMax(uwnd_o,True)
> ;================================================;
> ;================================================;
> end
>
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Received on Fri Oct 30 05:53:35 2009