Date: Sun, 2 Oct 2011 13:49:02 -0500
Reply-To: Joe Matise <snoopy369@GMAIL.COM>
Sender: "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From: Joe Matise <snoopy369@GMAIL.COM>
Subject: Re: How to input hex from string
In-Reply-To: <CAM+YpE-5PXB56JuC--AYN-1+psA743MfSE_KPjeNfakYmvAh3A@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
Err, try this...
http://core.ecu.edu/psyc/wuenschk/Images/SAS_logo.jpg
-Joe
On Sun, Oct 2, 2011 at 1:48 PM, Joe Matise <snoopy369@gmail.com> wrote:
> What do you get when you download this .jpg and run your code on it?
>
> -Joe
>
> On Sun, Oct 2, 2011 at 1:44 PM, Arthur Tabachneck <art297@rogers.com> wrote:
>> For the example I showed, leaving of the denominator, I get: -5819 rather
>> than the correct 23238. The only thing that should vary on any jpg that
>> contains gps info is whether the numbers are big or little endian.
>>
>> Interestingly, the method works correctly for all 1-digit numbers and for
>> e803 or 1000.
>>
>> Art
>> -----
>> On Sun, 2 Oct 2011 13:01:20 -0500, Joe Matise <snoopy369@GMAIL.COM> wrote:
>>
>>>What do you get when you run your code? I get values like that from
>>>my jpegs (not that exactly but I assume that varies).
>>>
>>>-Joe
>>>
>>>On Sun, Oct 2, 2011 at 12:43 PM, Arthur Tabachneck <art297@rogers.com>
>> wrote:
>>>> Joe,
>>>>
>>>> Yes, IBR2. is probably long enough. The following shows the kind of
>> numbers
>>>> I am trying to read. I know how to do it this way, but not getting the
>> info
>>>> from the substr function:
>>>>
>>>> data test;
>>>> latsec=input("c65a"x,ibr2.);
>>>> output;
>>>> run;
>>>>
>>>> That will correctly get the value 23238.
>>>>
>>>> Art
>>>> -------
>>>> On Sun, 2 Oct 2011 12:14:53 -0500, Joe Matise <snoopy369@GMAIL.COM>
>> wrote:
>>>>
>>>>>First, why are you specifying IBR8.? I think IBR2. is actually
>>>>>correct (though 8. probably doesn't hurt anything).
>>>>>
>>>>>Second, are you sure the characters are correctly being grabbed? What
>>>>>happens with IBR informat (if I understand correctly) is that it takes
>>>>>the underlying representation of the character (so for 'A' it would be
>>>>>'41'x or 01000001) and converts it to little endian number. That
>>>>>conversion should be easily defined and doable by hand. I get 65 for
>>>>>'A' or '41'x, which seems the same as if I use IB. (which if I
>>>>>understand correctly uses big endian), so not sure where/when they
>>>>>should be different. At this point we go off the page of what I know
>>>>>unfortunately, so if it's getting the correct characters but not
>>>>>translating it correctly you'll have to wait for one of our mainframe
>>>>>gurus :)
>>>>>
>>>>>-Joe
>>>>>
>>>>>On Sun, Oct 2, 2011 at 11:53 AM, Arthur Tabachneck <art297@rogers.com>
>>>> wrote:
>>>>>> I must have been sleeping in class when this topic was covered. I have
>> a
>>>>>> set of jpg files that I'm using a regular expression to find the
>> starting
>>>>>> location of a particular field. Everything works perfectly and I am
>> able
>>>> to
>>>>>> get the desired field.
>>>>>>
>>>>>> However, since it is an integer represented as hex with little endian
>>>>>> representation, I also need to use the ibr informat. The following
>>>> doesn't
>>>>>> work correctly:
>>>>>>
>>>>>> %let path=c:\art\;
>>>>>> filename indata pipe "dir &path.*.jpg /b";
>>>>>> data want (keep=fname lat: lon:);
>>>>>> length fil2read fname $80;
>>>>>> retain dt_pattern_num gps_pattern_num;
>>>>>> infile indata truncover;
>>>>>> if _n_ = 1 then do;
>>>>>> gps_pattern_num =PRXPARSE("/\x02\x02\x00\x00/");
>>>>>> end;
>>>>>> informat f2r $50.;
>>>>>> input f2r;
>>>>>> fil2read="&path."||f2r;
>>>>>> done=0;
>>>>>> infile dummy filevar=fil2read RECFM=N lrecl=12000
>>>>>> end=done;
>>>>>> fname=fil2read;
>>>>>> do while(not done);
>>>>>> input VAR1 $char12000.;
>>>>>> POSITIONL = PRXMATCH(GPS_PATTERN_NUM,var1);
>>>>>> latdiv=input(substr(var1,positionL+244,2),ibr8.);
>>>>>> latsec=input(substr(var1,positionL+240,2),ibr8.)/latdiv;
>>>>>> output;
>>>>>> done=1;
>>>>>> end;
>>>>>> run;
>>>>>>
>>>>>> Thus, my question is with respect to creating latdiv and latsec, how
>> does
>>>>>> one tell sas that the text being captured with the substr function
>>>>>> represents hex characters?
>>>>>>
>>>>>> Thanks in advance,
>>>>>> Art
>>>>>>
>>>>
>>
>
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