[ncl-talk] CMORPH Rainfall

[Dennis Shea]

Also ... *you* must read the documentation carefully. The documentation states:
             "Each direct access record is a 4948 x 1649 CHARACTER*1"

[1]
You are using 'fbinrecread' which is for fortran sequential records.
You should use 'fbindirread' which is for direct access records.

[2]
Ypu have 'lat' going from South-to-North. The documentation states the
data are N->S.

[3]
Since the max byte is 255, I think unsigned byte type should be used.


http://www.ncl.ucar.edu/Applications/
Under 'Datasets' ... Click 'High Res Precipitation'

Minor modifications to existing CMORPH examples resulted in cmorph_4.ncl


On Mon, Dec 21, 2015 at 6:46 AM, Rick Brownrigg <brownrig at ucar.edu> wrote:
> Hi,
>
> According to the docs at:
>
> ftp://ftp.cpc.ncep.noaa.gov/precip/global_CMORPH/README.cmorph.8km_30minute
>
> the data are given as unsigned bytes, not floats. This would explain the
> warning about file size.  By the comments in the GRADS definition, you
> multiply the cmorph values by 0.2 to get mm/hr. With that in mind, I *think*
> you need something like (untested!):
>
> cmorrf_ubytes   =    fbinrecread("test.bin",0,(/nlat,nlon/),"ubyte")
>
> cmorrf_ubytes at _FillValue = 255B
>
> cmorrf = cmorrf_ubytes * 0.2   ; convert to floats, units are mm/hr
>
>
> As a side note, since its byte data, the setfileoption(...) is superfluous.
>
> Hope that helps..
>
> Rick
>
>
> On Sun, Dec 20, 2015 at 4:39 AM, Geeta Geeta <geetag54 at yahoo.com> wrote:
>>
>> I have to plot 8km_30minutes resolution CMORPH rainfall.
>> The data is binary format. and has 24 files of each hour.
>>
>> -rw-r--r-- 1 aditya aditya 48955512 Dec  1 19:33
>> CMORPH_8KM-30MIN_2015113021
>> -rw-r--r-- 1 aditya aditya 48955512 Dec  1 19:33
>> CMORPH_8KM-30MIN_2015113022
>> -rw-r--r-- 1 aditya aditya 48955512 Dec  1 19:33
>> CMORPH_8KM-30MIN_2015113023
>>
>> As per the documentation of this data from
>> (ftp://ftp.cpc.ncep.noaa.gov/precip/global_CMORPH/CMORPH_8km-30-minute.ctl)
>>
>> DSET
>> /your-data-set-path/advt-8km-intrp-prim-sat-spat-2lag-2.5+5dovlp8kmIR-%y4%m2%d2%h2
>> OPTIONS yrev big_endian template
>> UNDEF  255
>> TITLE  correlation estimates
>> XDEF 4948 LINEAR   0.036378335 0.072756669
>> YDEF 1649 LINEAR -59.963614    0.072771377
>> ZDEF   01 LEVELS 1
>> TDEF 99999  LINEAR   00z21dec2002 30mn
>> VARS 3
>> cmorph   1  -1,40,1,-1 xxxxxx yyyyy  (mult. by 0.2 to get mm/hr units)
>> time     1  -1,40,1,-1 xxxxxx yyyyy
>> satid    1  -1,40,1,-1 xxxxxx yyyyy
>> ENDVARS
>>
>> there are 3 records, 1st record being the desired parameter.
>> (ftp://ftp.cpc.ncep.noaa.gov/precip/global_CMORPH/README.cmorph.8km_30minute).
>>
>> I have to plot each hourly file and then get 24 hrs rainfall for a day.
>>
>> ;;;;;;;Code;
>>
>>  print(isbigendian)
>>
>> ; ----Defining for Once -----
>>
>>   wks         = gsn_open_wks("ps","CMO-v1")
>>                 gsn_define_colormap(wks,"prcp_2")
>>
>>   nlat        =  1649
>>   nlon        =  4948
>> ;--------------------------------------------------
>>
>>  lat         = -59.963614 + ispan(0,nlat-1,1)*0.072771377
>> ;                 print(lat)
>>  lon         = 0.036378335 + ispan(0,nlon-1,1)*0.072756669
>> ;                 print(lon)
>>
>>                setfileoption("bin","ReadByteOrder","BigEndian")
>>
>> ; cmorrf   =    fbinrecread("test.bin",0,(/nlat,nlon/),"float")  ; print
>> 0th record.
>>
>>
>> cmorrf   =    fbinrecread("test.bin",0,-1,"float")  ; print 0th record.
>>
>>                 print("Sizeof rf  ="+dimsizes(cmorrf))
>> ;               print(cmorrf)
>>                 asciiwrite("rf.txt",cmorrf)
>>
>> When I run this,
>>
>> See http://www.ncl.ucar.edu/ for more details.
>> (0) False
>> warning:fbinrecread: size specified is greater than record size, filling
>> with missing values
>> (0) Sizeof rf  =1649
>> (1) Sizeof rf  =4948
>>
>> when I use -1 in line defining cmorphh, I get this output.
>>
>> aditya at agniilap:~/geeta/ncl/CMORPH$  See http://www.ncl.ucar.edu/ for more
>> details.
>> (0) False
>> (0) Sizeof rf  =0
>>
>>
>> no rainfall is written to the file.
>> Also the 1st and 2nd  records are not being shown.
>>
>> Pls suggest.
>>
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>
>
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