R help - Nov 2009 - Test Binary File

I've got an error with the way I'm using readBin on a binary file of
unknown internal structure.  I know the structure consists of rows and columns,
but I'm not sure how many of each.

So, does anyone know of a valid test set of binary data that I could reference
while trying to figure out the technique of using readBin?

It would be really helpful to try out readBin on a readily available and
understood binary file instead of starting with one of dubious internal
structure.

Thank you again for your help and feedback.

Do you know how it is structured?  Is it 64-bit floating point, 32-bit
floating point, 64 bit integer, 32 bit integer, byte values, etc.?  If
we know the structure, then we can determine how to decode the
information.

On Wed, Nov 25, 2009 at 7:34 AM, Jason Rupert <jasonkrupert at yahoo.com>
wrote:
> I've got an error with the way I'm using readBin on a binary file
of unknown internal structure. ?I know the structure consists of rows and
columns, but I'm not sure how many of each.
>
> So, does anyone know of a valid test set of binary data that I could
reference while trying to figure out the technique of using readBin?
>
> It would be really helpful to try out readBin on a readily available and
understood binary file instead of starting with one of dubious internal
structure.
>
> Thank you again for your help and feedback.
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>


-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?

On 25/11/2009 7:34 AM, Jason Rupert wrote:
> I've got an error with the way I'm using readBin on a binary file
of unknown internal structure.  I know the structure consists of rows and
columns, but I'm not sure how many of each.
>
> So, does anyone know of a valid test set of binary data that I could
reference while trying to figure out the technique of using readBin?
>
> It would be really helpful to try out readBin on a readily available and
understood binary file instead of starting with one of dubious internal
structure.
>   
You can write your own.  For example,

f <- tempfile()
writeBin(as.numeric(1:100), f)

The hexView package is very nice for seeing what you've got:

library(hexView)
viewRaw(f)

which will show something like this:

 0  :  00 00 00 00 00 00 f0 3f 00 00 00 00 00 00 00 40  |  .......?.......@
 16  :  00 00 00 00 00 00 08 40 00 00 00 00 00 00 10 40  |  ....... at .......@
 32  :  00 00 00 00 00 00 14 40 00 00 00 00 00 00 18 40  |  ....... at .......@
...

viewRaw(f, human="real")

will show

  0  :  00 00 00 00 00 00 f0 3f 00 00 00 00 00 00 00 40  |    1   2
 16  :  00 00 00 00 00 00 08 40 00 00 00 00 00 00 10 40  |    3   4
 32  :  00 00 00 00 00 00 14 40 00 00 00 00 00 00 18 40  |    5   6
 48  :  00 00 00 00 00 00 1c 40 00 00 00 00 00 00 20 40  |    7   8
...

Duncan Murdoch

As an alternative to the hexview package, an external Hex-Editor may help you
investigate how the data is organised.

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