From d3f6c1417a53eddb7f8c10810f311cec9b81f0f0 Mon Sep 17 00:00:00 2001 From: OLSSON Hans Date: Thu, 2 Sep 2021 14:27:17 +0200 Subject: [PATCH] Sentence linebreaks. Add note that variability is differently defined for variables and expressions. --- chapters/classes.tex | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/chapters/classes.tex b/chapters/classes.tex index 8b33206ca..c136397ce 100644 --- a/chapters/classes.tex +++ b/chapters/classes.tex @@ -346,17 +346,12 @@ \subsection{Component Variability Prefixes discrete, parameter, constant}\label{ \item A \emph{discrete-time} variable \lstinline!vd! is a variable declared with the \lstinline!discrete!\indexinline{discrete} prefix, or a variable without any prefix that is not a continuous-time variable. It has a vanishing time derivative between events. - Note that this is not the same as saying that \lstinline!der(vd)=0! almost everywhere, - as the derivative is not even defined at the events, and it is not legal - to apply \lstinline!der! to discrete-time variables as they are not continuous. + Note that this is not the same as saying that \lstinline!der(vd)=0! almost everywhere, as the derivative is not even defined at the events, and it is not legal to apply \lstinline!der! to discrete-time variables as they are not continuous. During transient analysis the variable can only change its value at event instants (see \cref{events-and-synchronization}). \item - A continuous-time variable is a \lstinline!Real! variable without any prefix that is not assigned in a \lstinline!when!-clause. - A \emph{continuous-time} variable \lstinline!vn! may have a non-vanishing time - derivative (\lstinline!der(vn)<>0! possible) and may also - change its value discontinuously at any time during transient analysis - (see \cref{events-and-synchronization}). If there are any discontinuities the variable is - not differentiable. + A \emph{continuous-time} variable is a \lstinline!Real! variable without any prefix that is not assigned in a \lstinline!when!-clause. + A continuous-time variable \lstinline!vn! may have a non-vanishing time derivative (\lstinline!der(vn)<>0! possible) and may also change its value discontinuously at any time during transient analysis (see \cref{events-and-synchronization}). + If there are any discontinuities the variable is not differentiable. \end{itemize} Components declared as \lstinline!constant! shall have an associated declaration equation with a constant expression, if the constant is directly in the simulation model, or used in the simulation model. @@ -388,6 +383,9 @@ \subsection{Component Variability Prefixes discrete, parameter, constant}\label{ definition equations is given in \cref{variability-of-expressions}. \begin{nonnormative} +Note that for expressions discrete-time expressions include parameter expressions, whereas discrete-time variables do not include parameter variables. +This is consistent with restrictions on variability for expressions normally being upper limits. + For \lstinline!Real! variables we can distinguish two subtly different categories: discrete-time and piecewise constant, where the discrete-time variables are a subset of all piecewise constant variables. The \lstinline!Real! variables declared with the prefix \lstinline!discrete! is a subset of the discrete-time \lstinline!Real! variables. For a \lstinline!Real! variable, being discrete-time is equivalent to being assigned in a \lstinline!when!-clause.