Re: read TRMM version 7 Level 2 hdf file

The hex output seems to happen when you combine a string and a hex value:

ncl 0> x=1b
ncl 1> print(x)
Variable: x
Type: byte
Total Size: 1 bytes
            1 values
Number of Dimensions: 1
Dimensions and sizes: [1]
Coordinates:
(0) 1
ncl 2> print(""+x)
(0) 0x01

¡ªMary

On Mar 30, 2014, at 11:50 AM, David Brown <dbrown@ucar.edu> wrote:

> Hi Yen,
> This actually seems quite strange because recent versions of NCL do *not* print the byte type using hexadecimal numbers.
> I am not sure how you can have NCL 6.1.2 printing hexadecimal values for the byte type.
>
> Also in version 6.0.0 the byte type was changed from unsigned (ranging from 0-255) to signed (ranging from -128 to +127).
> The ubyte type was added as the unsigned type. In case you didn't realize it, the signed value -99 has the some underlying bit pattern as the
> unsigned value 157. You can use the functions 'tounsigned' and 'tosigned' convert back and forth between any unsigned integer type and its
> signed version.
>
> So:
> ncl 8> print(tosigned(157B)) ; B is the suffix for unsigned byte (ubyte)
> (0) -99
> ncl 9> print(tounsigned(-99b)) ; b is the suffix for byte
> (0) 157
>
>
>
> On Mar 29, 2014, at 8:38 PM, yinjinfang88 <yinjinfang88@163.com> wrote:
>
>>
>> Dear all£¬
>> Thank you very much for your reply. I still get a wrong result following your method. There are as follows:
>> $ ncl
>> Copyright (C) 1995-2013 - All Rights Reserved
>> University Corporation for Atmospheric Research
>> NCAR Command Language Version 6.1.2
>> The use of this software is governed by a License Agreement.
>> See http://www.ncl.ucar.edu/ for more details.
>> ncl 0> f = addfile("2A12.20100101.69095.7.HDF","r") ; Add file
>> ncl 1> fzHIndex = f->freezingHeightIndex ; read freezingHeightIndex
>> ncl 2> printVarSummary(fzHIndex)
>>
>> Variable: fzHIndex
>> Type: byte
>> Total Size: 607568 bytes
>> 607568 values
>> Number of Dimensions: 2
>> Dimensions and sizes: [nscan | 2921] x [npixel | 208]
>> Coordinates:
>> Number Of Attributes: 1
>> hdf_name : freezingHeightIndex
>>
>> ncl 3> print("fzHIndex: min="+min(fzHIndex)+" max="+max(fzHIndex))
>> (0) fzHIndex: min=0x01 max=0x9d
>>
>> ncl 4> print("fzHIndex: min="+min(toshort(fzHIndex))+" max="+max(toshort(fzHIndex)))
>> (0) fzHIndex: min=1 max=157
>>
>> ncl 5> print("fzHIndex: min="+min(toshort(fzHIndex))+" max="+max(toshort(fzHIndex)))
>> (0) fzHIndex: min=1 max=157
>>
>> ncl 6> print("fzHIndex: min="+toshort(min(fzHIndex))+" max="+toshort(max(zHIndex)))
>> (0) fzHIndex: min=1 max=157
>>
>> ncl 8> print("fzHIndex: min="+min(toint(fzHIndex))+" max="+max(toint(fzHIndex)))
>> (0) fzHIndex: min=1 max=157
>>
>> ncl 9> print("fzHIndex: min="+toint(min(fzHIndex))+" max="+toint(max(fzHIndex)))
>> (0) fzHIndex: min=1 max=157
>>
>> ==============================
>> The results should be "(0) fzHIndex: min=-99 max=13".
>> However, NCL got strange results. I am confused whether it is related to the computer hardware. I run NCL in unix of AIX.
>>
>> The returns of uname and gcc commands are shown
>>
>> $uname -a
>> AIX cma18n01 1 7 0007471BD400
>>
>> $gcc --version
>> gcc (GCC) 4.8.1
>> Copyright (C) 2013 Free Software Foundation, Inc.
>> This is free software; see the source for copying conditions. There is NO
>> warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
>>
>>
>>
>> Thanks.
>>
>> Yin
>>
>> Yin Jin-Fang
>> State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081, China
>> _______________________________________________
>> ncl-talk mailing list
>> List instructions, subscriber options, unsubscribe:
>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>
> _______________________________________________
> ncl-talk mailing list
> List instructions, subscriber options, unsubscribe:
> http://mailman.ucar.edu/mailman/listinfo/ncl-talk

_______________________________________________
ncl-talk mailing list
List instructions, subscriber options, unsubscribe:
http://mailman.ucar.edu/mailman/listinfo/ncl-talk
Received on Sun Mar 30 18:32:01 2014