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From: Richard Gueler on 15 Jul 2010 21:58
I am reading bunch of binary data from a device that is mixed with various datatypes. The binary data is read in as a "uint8" array. I need to convert this binary data to other various datatypes. For example, elements 40-47 in the array represent a "double". Elements 36-37 are a "uint16". Any suggestions on how I can convert this binary data to the other datatypes?
From: Walter Roberson on 15 Jul 2010 23:04
Richard Gueler wrote:
> I am reading bunch of binary data from a device that is mixed with
> various datatypes. The binary data is read in as a "uint8" array. I
> need to convert this binary data to other various datatypes. For
> example, elements 40-47 in the array represent a "double". Elements
> 36-37 are a "uint16". Any suggestions on how I can convert this binary
> data to the other datatypes?

See typecast()

However, if you have an external binary file, the representation of
"double" or "uint16" might not be the same as in your Matlab; in
particular, the byte ordering might be different even if the same IEEE
754 binary arithmetic standard was used.
From: Steven Lord on 15 Jul 2010 23:22

"Walter Roberson" <roberson(a)hushmail.com> wrote in message
news:J_P%n.22423$4B7.5584(a)newsfe16.iad...
> Richard Gueler wrote:
>> I am reading bunch of binary data from a device that is mixed with
>> various datatypes. The binary data is read in as a "uint8" array. I
>> need to convert this binary data to other various datatypes. For
>> example, elements 40-47 in the array represent a "double". Elements
>> 36-37 are a "uint16". Any suggestions on how I can convert this binary
>> data to the other datatypes?
>
> See typecast()
>
> However, if you have an external binary file, the representation of
> "double" or "uint16" might not be the same as in your Matlab; in
> particular, the byte ordering might be different even if the same IEEE 754
> binary arithmetic standard was used.

In which case the OP may need to use SWAPBYTES in conjunction with TYPECAST,
or to open the file using FOPEN with a specific endian-ness.

--
Steve Lord
slord(a)mathworks.com
comp.soft-sys.matlab (CSSM) FAQ: http://matlabwiki.mathworks.com/MATLAB_FAQ
To contact Technical Support use the Contact Us link on
http://www.mathworks.com


From: Richard Gueler on 16 Jul 2010 10:25
"Steven Lord" <slord(a)mathworks.com> wrote in message <i1ojah$h1d$1(a)fred.mathworks.com>...
>
> "Walter Roberson" <roberson(a)hushmail.com> wrote in message
> news:J_P%n.22423$4B7.5584(a)newsfe16.iad...
> > Richard Gueler wrote:
> >> I am reading bunch of binary data from a device that is mixed with
> >> various datatypes. The binary data is read in as a "uint8" array. I
> >> need to convert this binary data to other various datatypes. For
> >> example, elements 40-47 in the array represent a "double". Elements
> >> 36-37 are a "uint16". Any suggestions on how I can convert this binary
> >> data to the other datatypes?
> >
> > See typecast()
> >
> > However, if you have an external binary file, the representation of
> > "double" or "uint16" might not be the same as in your Matlab; in
> > particular, the byte ordering might be different even if the same IEEE 754
> > binary arithmetic standard was used.
>
> In which case the OP may need to use SWAPBYTES in conjunction with TYPECAST,
> or to open the file using FOPEN with a specific endian-ness.
>
> --
> Steve Lord
> slord(a)mathworks.com
> comp.soft-sys.matlab (CSSM) FAQ: http://matlabwiki.mathworks.com/MATLAB_FAQ
> To contact Technical Support use the Contact Us link on
> http://www.mathworks.com
>

It worked! I had to swap the byte ordering. I did the following:

new_data = swapbytes(typecast(data(40:47),'double'))

Thanks
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