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<p class="MsoNormal">Dear TRNSYS users,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I have been looking for a while to the seventh section of the TRNSYS 17 manual in order to understand how and why the kernel calls a type in the way it does.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Notwithstanding my experience with simulation software like Matlab/Simulink, Scilab/XCos, Ptolemy II, I still have difficulties in understanding some aspects of the TRNSYS callbacks interface, e.g.:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoListParagraph" style="margin-left:20.25pt;text-indent:-18.0pt;mso-list:l0 level1 lfo1">
<![if !supportLists]><span style="mso-list:Ignore">1)<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>What’s the purpose of the inter-step calls (iterations)<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:20.25pt;text-indent:-18.0pt;mso-list:l0 level1 lfo1">
<![if !supportLists]><span style="mso-list:Ignore">2)<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>Why they need to be exactly 3 (as I understood from the manual).<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:20.25pt;text-indent:-18.0pt;mso-list:l0 level1 lfo1">
<![if !supportLists]><span style="mso-list:Ignore">3)<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>How the kernel make use of the vector dTdt (which I would have called dxdt).<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:20.25pt;text-indent:-18.0pt;mso-list:l0 level1 lfo1">
<![if !supportLists]><span style="mso-list:Ignore">4)<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>Whether my understanding that Types can be used to implement the following mathematical models: y = g(x, u, t), dxdt = fc(x, u, t) (or x(t+1) = fd(x(t), u(t), t) in case of discrete systems), where t is the time, u is the input vector,
x is the state vector and y is the output vector is correct.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Can anybody suggest me what is the right section of the manual to find an answer to these questions? I had no luck reading the programmer´s guide section of the manual.<o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal">A second point is that I found puzzling the code example published therein. In the first time I though that my doubts where related to my scarce knowledge of the Fortran language (I am a C/C++ programmer) so I raised a point in a programmer
community <a href="http://stackoverflow.com/questions/15414277/where-does-fortran-store-local-variables">
http://stackoverflow.com/questions/15414277/where-does-fortran-store-local-variables</a> . It turned out that the code published in the manual (which contains a pattern which I noticed has widespread to many other types) seems to rely on a Fortran language
“feature” which is considered “bad programming practice”, is compiler-dependent and may not be supported any more in the future.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">As it seem to me impossible that such a “bomb” is present in the program without affecting the TRNSYS community I kindly ask the help of a TRNSYS expert to clarify this point.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Does anybody know if there a trnsys-devel mailing list?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Sincerely,<o:p></o:p></p>
<p class="MsoNormal"> AS<o:p></o:p></p>
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