% free-fall.tex — single-stock numerical model.
%
% A ball dropped from y0 = 100 m under constant gravity.  One
% Forrester stock for height (Y), one for velocity (V), and an
% auxiliary integrator for time (T).  \diagrammodel renders Y(T).

\documentclass{article}
\usepackage[syntax=NL]{numodel}
\usepackage[a4paper, margin=0.5cm]{geometry}

\begin{document}

\def\dgridx{2}\def\dgridy{2}
% === COMPUTERMODEL ===
%\numodelsetup{diagram-style=forrester, flowarrow-cloud-tip=true}
\numodelsetup{diagram-style=tight, flowarrow-cloud-tip=false, gridmaxx=6}
\newmodelprefix{lift}

\mvar{T}{t}{0}{\s}{2}{system}
\mvar{Dt}{dt}{0.03}{\s}{1}{system}
\mvar{Tend}{T}{5.6}{\s}{2}{system}

\mvar{J}{j}{1.1}{\m\per\s^3}{2}{constant}
\mvar{G}{g}{9.81}{\m\per\s\squared}{3}{constant}
\mvar{Mcab}{m_{cab}}{700}{\kg}{3}{constant}
\mvar{Mcon}{m_{con}}{400}{\kg}{3}{constant}
\mvar{Frol}{F_{rol}}{40}{\N}{2}{constant}

\mvar{FzCab}{F_{Z,cab}}{}{\N}{3}{hulp}
\mvar{FzCon}{F_{Z,con}}{}{\N}{3}{hulp}
\mvar{FzNet}{F_{Z,net}}{}{\N}{3}{hulp}
\mvar{Fmotor}{F_{motor}}{}{\N}{3}{hulp}

\mvar{EZ}{E_Z}{}{\J}{3}{stock}
\mvar{Esys}{E_{sys}}{}{\J}{3}{stock}
\mvar{Pout}{P_{out}}{}{\W}{3}{hulp}
\mvar{dMGV}{dMGV}{}{\W}{3}{hulp}

%\mvar[gridx=1,gridy=-1]{A}{a}{0}{\m\per\s\squared}{2}{stock}
\mvar{A}{a}{0}{\m\per\s\squared}{2}{stock}
\mvar{V}{v}{0}{\m\per\s}{1}{stock}
\mvar{H}{h}{0}{\m}{1}{stock}

\mrule{FzCab}{\liftMcab * \liftG}
\mrule{FzCon}{\liftMcon * \liftG}
\mrule{FzNet}{\liftFzCab - \liftFzCon}
\mrule*{A}{(\liftT < \liftTend / 4) || (\liftT > \liftTend * 3 / 4) ? \liftA + \liftJ * \liftDt : \liftA - \liftJ * \liftDt}
\mrule{V}{\liftV + \liftA * \liftDt}
\mrule[aliasright=\cdots]{H}{\liftH + \liftV * \liftDt}
\mrule[aliasright=\cdots]{Fmotor}{(\liftMcab + \liftMcon) * \liftA + \liftFzNet + \liftFrol}
\mrule{dMGV}{(\liftMcab-\liftMcon)*\liftG * \liftV}
\mrule{Pout}{\liftFrol * \liftV}
\mrule{EZ}{\liftEZ - \liftdMGV * \liftDt}
\mrule{Esys}{\liftEsys - \liftPout * \liftDt + \liftdMGV * \liftDt}
\mrule{T}{\liftT + \liftDt}
\mstop{\liftT >= \liftTend}

\section*{Tekstmodel}
\textmodel

\section*{Grafisch Model}
\graphicmodel
\directlua{
  local f = io.open("showcase.layout.txt","w")
  f:write(numodel.dump_layout("lift")); f:close()
}

% Simulatie
\computemodel

\section*{Diagram}
\def\ycmmax{8}
\diagrammodel{T}{H}{lift}


\section*{forrester + per-mvar cloud=false on the stock}
\numodelsetup{diagram-style=forrester, flowarrow-cloud-tip=true}
\newmodelprefix{d}
\mvar{T}{t}{0}{\s}{2}{system}
\mvar{Dt}{dt}{1}{\s}{2}{system}
\mvar[flowarrow-cloud-tip=true]{N}{n}{0}{}{0}{stock}
\mvar{R}{r}{5}{\per\s}{2}{constant}
\mrule{N}{\dN + \dR * \dDt}
\mrule{T}{\dT + \dDt}
\mstop{\dT >= 5}
\textmodel
\graphicmodel
\computemodel

\end{document}