[PD] PD Float accuracy

[Roman Haefeli]

On Fri, 2008-11-07 at 09:45 +0100, IOhannes m zmoelnig wrote:
> Mark Sexton wrote:
> > Hi
> > I need PD to make simple but accurate calculations for a sonification project. However there seems to be a problem working accurately with floats that have 7 or more digits in total (before or after the decimal point). PD always seem to round the figure to 6 digits whether in a calculation, or even typing a 7+ digit float into a number box e.g. 1234.5678 rounded to 1234.57
> > 
> > I've got a couple of ugly hacks to work around for now, but it seems a fairly fundamental thing to do, so would be grateful to hear if I'm missing a simple way to get PD to work accurately with floats of any arbitrary length above 6 digits.
> > 
> 
> you don't need anything.
> Pd does uses IEEE floating point values for numbers, you don't loose a
> single bit.
> it's only the GUI that likes to round the numbers when displaying it.
> internally everything is "correct" (as far as it is possible using
> single precision floats)
> 
> you could change the "width" of a number-box to see more digits.

still only 6 digits are displayed. altough pd works internall with IEEE
32bit floating values, i couldn't think of an easy way to get them out
of pd. both, print and the numberbox truncate the numbers. 

two ways - not very feasible, though - to get full precision out of pd
come to my mind:

- send the numbers over OSC to some other application
- write the numbers to an audio file with 32bit bitlength. extract the
numbers from there

or has someone a better idea?

roman


	
		
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