On Thursday, April 26, 2018, 4:30:47 AM EDT, hans w. koch hansw.koch@gmail.com wrote:
thanks orm and cyrille
for forcing me to acknowledge, that i´ve indeed hit the IEEE ceiling here. i stubbornly tried to turn a blind eye to that...
i am using pd 48-1 in 64bit but to my understanding internally it stil computes single precision.
and the copy of pd-double floating around, doesn´t provide the lovely amenities of the text objects, on which most of my operations rely.
There is a student working on double-precision t_float in Purr Data as part of GSoC this summer. -Jonathan
maybe its finally time to look into python…
all best
hans
Am 26.04.2018 um 10:13 schrieb Orm Finnendahl orm.finnendahl@selma.hfmdk-frankfurt.de:
Hi Hans,
this is related to the integer precision of float numbers. In 32-bit pd to my knowledge single-floats as specified here are used:
https://en.wikipedia.org/wiki/IEEE_754
To be able to use bigger integers you can cascade more than one number (like hours/minutes/seconds in a clock), if you want to calculate aith these, implement abstractions for the needed mathematical functions, using e.g. list representations of the individual numbers as in/output.
Unfortunately this is also related to indexing into arrays limiting the maximum address.
Another solution could be to use 64-bit pd with double float resolution.
-- Orm
Am Donnerstag, den 26. April 2018 um 09:57:35 Uhr (+0200) schrieb hans w. koch:
thanks, cyrille,
but why does the computation for 5pow12 [print start] in my patch then still produce 2.44141e+08? or 5pow12 - 4pow12 work? (see attached)
cheers hans
Am 26.04.2018 um 09:46 schrieb cyrille henry ch@chnry.net:
hello,
this is not a probem with until, but a problem of big number precision. see attachment. cheers c
Le 26/04/2018 à 09:30, hans w. koch a écrit :
dear miller, all for a project i am working with very high number of iterations. but it seems i´ve literally hit a ceiling with [until] for 4pow12 iterations it performs fine. but 5pow12 doesn´t. feeding it into a counter, 5pow12 produces the same result as 4pow12. attached a small patch to demonstrate. is this limitation by purpose? (i have a workaround not using [until], but wanted to make sure i didn´t overlook something) thanks hans _______________________________________________ Pd-list@lists.iem.at mailing list UNSUBSCRIBE and account-management -> https://lists.puredata.info/listinfo/pd-list
<big_number_precision.pd>_______________________________________________ Pd-list@lists.iem.at mailing list UNSUBSCRIBE and account-management -> https://lists.puredata.info/listinfo/pd-list
Pd-list@lists.iem.at mailing list UNSUBSCRIBE and account-management -> https://lists.puredata.info/listinfo/pd-list
Pd-list@lists.iem.at mailing list UNSUBSCRIBE and account-management -> https://lists.puredata.info/listinfo/pd-list