[PD] counter question

Mathieu Bouchard matju at artengine.ca
Thu Jul 26 23:06:53 CEST 2007


On Fri, 27 Jul 2007, Andy Farnell wrote:

> No, it will always use sizeof(float) ehatever is stuck in it. Probably 4 bytes.

float is always 4 bytes. On 64-bit machines, a float word will use 8 
bytes, 4 of which will be unused, because float is always 4 bytes.

> Sometimes it wraps, so if the maximum value  is n then it goes
> {...n-2, n-1, n, -n-1, -n, -n+1...}

This is for the int format, which is not supported by Pd, but can happen 
inside of [expr] because it was written for jMax/FTS. This can also happen 
in GridFlow when using one of the four different int formats. For usual pd 
messages, this won't happen.

> ie overflow doesn't thow an exception and it just stays with the max 
> value there.

Technically it's not overflow of the floats, it's lack of precision of 
floats. However, in terms of the possible ints inside the float format, 
it's fair to call it an overflow. If you get a true float overflow you 
will reach a special value called "Infinity" but really it just means "Too 
Big".

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| Mathieu Bouchard - tél:+1.514.383.3801, Montréal QC Canada


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