[erlang-questions] undefined function erlang:binary_to_float/1

[Tony Rogvall]

On 18 jul 2013, at 13:19, Schneider <js@REDACTED> wrote:

> yea, this should work. But It's looks like my Problem is a little bit more complicated:
> 
> I have a C client sending some Data via UDP. And I want to write a Erlang program receiving this data.
> 
> the Data is of the form {unsigned long, float} (both stored as 4Byte values) but the binary I receive is of the form {int, int}.
> How can i convert the second one to an erlang float?
> 

If the data is sent on the same machine without endian handling (byte order) then you can match (binary) data like:

	<<Long:32/unsigned-integer-native, Float:32/float-native>>

You can change native to 'big' or 'little' if that byte order used. Files formats and network protocol mostly select
a byte order or flag it some how in the protocol specification. 
Hint. For intel based machines little endian is used. PowerPC / M680xx are big endian.

/Tony



> bg,
> Johannes
> 
> On Wed 17 Jul 2013 04:30:45 PM CEST, Wes James wrote:
>> Alternative for now??
>> 
>> list_to_float(binary:bin_to_list(<<"10.0">>)).
>> 10.0
>> 
>> 
>> On Wed, Jul 17, 2013 at 8:02 AM, Schneider <js@REDACTED
>> <mailto:js@REDACTED>> wrote:
>> 
>>    Hi List,
>> 
>>    I cannot find the function binary_to_float/1.
>> 
>>    using Erlang R14B04 (erts-5.8.5) on ubuntu precise.
>>    What do I miss?
>> 
>>    bg,
>>    Johannes
>> 
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> 
> 
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