| Re: Combine ascii and binary format (i.e. formatted and unformatted) [message #19742] |
Fri, 14 April 2000 00:00  |
Craig Markwardt
Messages: 1869
Registered: November 1996
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Senior Member |
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"Vince Hradil" <hradilv@yahoo.com> writes:
> Won't this work?
[ see below ]
I think it won't. The point was that the first number, myInteger, was
printed with formatted I/O, while the data itself was unformatted
binary.
In this situation I believe it's best to dispense with format
statements and do it the hard way. Formatted I/O leaves the file
pointer in an unpredictable position (*before* or *after* the space?),
and there's no efficiency lost when you're reading a few characters.
My suggestion:
myInteger = 0
myBlank = 0B
myArray = dblarr(sizeOfMyArray)
openr, lun, 'filename', /get_lun
readf, lun, myInteger ;; Formatted I/O
point_lun, lun, 0L ;; Rewind
repeat readu, lun, myBlank until string(myBlank) EQ ' ' ;; Skip past space
readu, lun, myArray ;; Unformatted I/O
free_lun, lun
This is the first time I have ever used "repeat" by the way.
Craig
>
> myInteger = 0
> myBlank = 0B
> myArray = dblarr(sizeOfMyArray)
>
> openr, lun, 'filename', /get_lun
> readu, lun, myInteger
> readu, lun, myBlank
> readu, lun, myArray
> close, lun
>
> "Nicolas Decoster" <Nicolas.Decoster@Noveltis.fr> wrote in message
> news:38F74DBF.AEDC4EC@Noveltis.fr...
>> Hi !
>>
>> I have (once again) a newbie question.
>>
>> I need to read files I created using C. They have the following format:
>> an ascii integer, followed by a blank space followed (with no new line)
>> by a binary array of double. In C, these files are created like that:
>>
>> fprintf(fileID, "%d ", myInteger);
>> fwrite(myArray, sizeof(double), sizeOfMyArray, fileID);
>>
>> Does someone know how I can read such files with IDL ? I tried, but I
>> can't figure how to specify the format string to read my integer, the
>> space after it and nothing else, so that I can get my array with a
>> simple readu.
>>
>> Thanks for any help.
>>
>> Nicolas.
>>
>> --
>> T�l. : 00 (33) 5 62 88 11 16
>> Fax : 00 (33) 5 62 88 11 12
>> Nicolas.Decoster@Noveltis.fr
>>
>> Noveltis
>> Parc Technologique du Canal
>> 2, avenue de l'Europe
>> 31520 Ramonville Saint Agne - France
>
>
--
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Craig B. Markwardt, Ph.D. EMAIL: craigmnet@cow.physics.wisc.edu
Astrophysics, IDL, Finance, Derivatives | Remove "net" for better response
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