Re: [SOSlib-devel] MathML Piecewise function[Scanned]

[Andrew F. <af...@ph...>]

Rainer

You are right this is a bug in the test suite

Andrew=20

> -----Original Message-----
> From: Rainer Machne [mailto:ra...@tb...]=20
> Sent: 16 June 2006 12:23
> To: Andrew Finney
> Cc: SOSlib Development
> Subject: MathML Piecewise function[Scanned]
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> hi Andrew,
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> The use of piecewise in the semantic test suite seems to=20
> differ from official definitions:
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> E.g. in discontinuityTimeAndDelay-geq-l2.xml
> it's:
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>   <piecewise>
>     <piece>
>       <apply>
>         <geq/>
>         <ci> s2 </ci>
>         <cn> 4 </cn>
>       </apply>
>       <cn>1.5</cn>
>     </piece>
>     <otherwise>
>        <cn>0.05</cn>
>     </otherwise>
> </piecewise>
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> which is
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> piecewise(geq(s2, 4), 1.5, 0.05)
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> in libSBML infix and interpreted as
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> 1.5 if s2 >=3D 4
> and
> 0.05 otherwise
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> by SOSlib.
> SOSlib produces the results required by the testsuite.
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> However, at
> http://www.w3.org/TR/MathML2/chapter4.html#contm.piecewise
> the definition is slightly different:
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> <piecewise>
>    <piece>
>        <cn> 0 </cn>
>        <apply><lt/><ci> x </ci> <cn> 0 </cn></apply>
>    </piece>
>    <otherwise>
>        <ci> x </ci>
>    </otherwise>
> </piecewise>
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> in libSBML infix
> piecewise(0, lt(x, 0), x)
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> interpreted as
> 0 if x < 0
> and x otherwise.
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> Note, that the if condition of the piece element is BEFORE=20
> the associated result, while it is AFTER the result in the=20
> test suite example.
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> The same ordering is found in the piecewise example for more=20
> pieces - see below. The result associated with a piece is=20
> always BEFORE the condition.
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> Am i missing something or is the test suite example (and=20
> SOSlib) wrong?
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> Rainer
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>=20
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> The general example with more pieces:
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> <piecewise>
>    <piece>
>        <apply><minus/><ci> x </ci></apply>
>        <apply><lt/><ci> x </ci> <cn> 0 </cn></apply>
>    </piece>
>    <piece>
>        <cn> 0 </cn>
>        <apply><eq/><ci> x </ci> <cn> 0 </cn></apply>
>    </piece>
>    <piece>
>        <ci> x </ci>
>        <apply><gt/><ci> x </ci> <cn> 0 </cn></apply>
>    </piece>
> </piecewise>
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