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Re: frozen value for discrete animation

From: Sjoerd Mullender <sjoerd@acm.org>
Date: Fri, 25 May 2007 14:21:17 +0200
Message-ID: <4656D4BD.1000201@acm.org>
To: Patrick Schmitz <cogit@ludicrum.org>
CC: "Dr. Olaf Hoffmann" <Dr.O.Hoffmann@gmx.de>, www-smil@w3.org
Patrick Schmitz wrote:
> By even multiple we intended that it was an integer multiple, with no
> fractional or partial multiple result.  We should probably have said
> "integer multiple". To be really precise we would have to specify an
> (integer>0) multiple.
> Our intent with "some" positive integer is "any". This is an English
> expression, common in mathematical descriptions. Sorry for any confusion.

I propose to change the wording to "integral multiple" to make it clear
that we're talking about proper multiples here.  Alternatively, we could
just leave out the word "even", but I think (as apparently the original
author did also) that an extra adjective should make it even clearer.

Sjoerd (member of the SYMM working group, so in a position to effect the

> Patrick
>> -----Original Message-----
>> From: www-smil-request@w3.org [mailto:www-smil-request@w3.org]On Behalf
>> Of Dr. Olaf Hoffmann
>> Sent: Friday, April 06, 2007 7:43 AM
>> To: www-smil@w3.org
>> Subject: Re: frozen value for discrete animation
>> Hello,
>> I think there is another problem concerning frozen animation,
>> maybe just a wording problem. I discussed this with several
>> people, but the result was always the same, but from my point of
>> view somehow useless for animation, but maybe I am wrong with this.
>> For 'Freezing animations' (SMIL 2.1, 3.3.5) it is noted:
>> 'If AD is an even multiple of d, i.e. AD = d*i for some positive
>>  integer i , and the animation is non-cumulative, f_f(t) = f(d).'
>> There a two remarkable points about this - why only 'some' and not
>> 'any' or 'a' positive integer and why only even multiples, why not
>> odd multiples too?
>> Ok, if odd multiples are excluded by this rule, this means that
>> some integers are only even integers, but then it should be much
>> more precise to write:
>> 'AD = d*2*i for a positive integer i'
>> Of course 'even' can have several meanings, therefore
>> I looked for another interpretation for 'even multiple'
>> in wikipedia and other resources, but all I could find is
>> really:
>> 'AD = d*2*i for a positive integer i'.
>> I cannot see, why to distinguish between odd and even
>> multiples? Is there any reason?
>> This causes another problem for odd multiples, because then
>> the following has to be applied:
>> 'If AD is not an even multiple of the simple duration d,
>>  f_f(t) = f_i(t), where i = floor(t/d).'
>> For example with AD=d (odd multiple) we get 1 = floor(d/d)
>> f_f(t=AD) = f_1(t=0)
>> if the animation is repeated (and stopped for example with
>> an end attribute) and an undefined value, if the animation
>> is not repeated. Is this correct?
>> Thanks in advance for a clarification
>> Olaf Hoffmann

Sjoerd Mullender

Received on Friday, 25 May 2007 12:21:54 UTC

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