Re: Big integers exported in scientific notation in XML
Re: Big integers exported in scientific notation in XML
- Subject: Re: Big integers exported in scientific notation in XML
- From: Marshall Eubanks <email@hidden>
- Date: Wed, 2 Sep 2009 21:03:21 -0400
On Sep 2, 2009, at 8:29 PM, Bruce Sharpe wrote:
I have just discovered that if a project contains a clip that has
more than a million frames (4.6 hours at 60 fps would do it), then
numbers like duration, in, out, etc. will be exported in the XML in
scientific notation.
Example:
Expected value: <duration>1234567</duration>
Exported value: <duration>1.23457e+06</duration>
Aside from the fact that it messes up everyone who is expecting an
integer there is a loss of precision. The difference between
1234567 and 1234570 frames could be important in some contexts.
Is this a known bug?
Single precision has 24 bits of precision, or about 6 x 10^-8
fractionally. So, that would be 0.07 for your example, and should be
marginally OK. However, in dealing with Julian Dates (about 2,500,000
days since the initial epoch, or an error of 0.15) we found that this
is dangerous. With even a little bit of manipulation (subtract this
value from that, and add to a third), you run the risk of being off by
a day (or, in this case, a frame).
So, in my opinion, these really should be double precision if they are
going to be real numbers.
Regards
Marshall
Bruce
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