766 lines
23 KiB
TeX
766 lines
23 KiB
TeX
\documentclass{beamer}
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\usepackage[utf8]{inputenc}
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\usepackage[T1]{fontenc}
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\usepackage{lmodern}
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\usepackage{amsmath}
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\usepackage[copyright]{ccicons}
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\usetheme{Boadilla}
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\titlegraphic{\includegraphics{../logos/dlogo.png}}
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\title{The Dynare Macro Processor}
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\author[S. Villemot, H.Bastani]{Sébastien Villemot \and Houtan Bastani}
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\institute[CEPREMAP]{\includegraphics[scale=0.15]{../logos/cepremap.jpg}}
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\date{28 June 2019}
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\setbeamertemplate{title page}
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{
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\vbox{}
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\begingroup
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\centering
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{\usebeamercolor[fg]{titlegraphic}\inserttitlegraphic\par}\vskip1em
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\begin{beamercolorbox}[sep=8pt,center]{title}
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\usebeamerfont{title}\inserttitle\par%
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\ifx\insertsubtitle\@empty%
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\else%
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\vskip0.25em%
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{\usebeamerfont{subtitle}\usebeamercolor[fg]{subtitle}\insertsubtitle\par}%
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\fi%
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\end{beamercolorbox}%
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\vskip1em\par
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\begin{beamercolorbox}[sep=8pt,center]{author}
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\usebeamerfont{author}\insertauthor
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\end{beamercolorbox}
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\begin{beamercolorbox}[sep=8pt,center]{institute}
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\begin{beamercolorbox}[sep=8pt,center]{date}
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\usebeamerfont{date}\insertdate
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\end{beamercolorbox}
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\endgroup
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\vfill
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}
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\AtBeginSection[]
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{
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\begin{frame}
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\frametitle{Outline}
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\tableofcontents[currentsection]
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\end{frame}
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}
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\begin{document}
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\begin{frame}
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\titlepage
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\begin{columns}[T]
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\column{0.2\textwidth}
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\column{0.09\textwidth}
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\ccbysa
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\column{0.71\textwidth}
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\tiny
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Copyright © 2008--2019 Dynare Team \\
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Licence: \href{http://creativecommons.org/licenses/by-sa/4.0/}{Creative
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Commons Attribution-ShareAlike 4.0}
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\end{columns}
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\end{frame}
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\begin{frame}
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\frametitle{Outline}
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\tableofcontents
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\end{frame}
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\section{Overview}
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\begin{frame}
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\frametitle{Motivation}
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\begin{itemize}
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\item The \textbf{Dynare language} (used in \texttt{.mod} files) is well suited for many economic models
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\begin{itemize}
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\item It's a markup language that defines models
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\item Lacks a programmatic element
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\end{itemize}
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\item The \textbf{Dynare macro language} adds a programmatic element to Dynare
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\begin{itemize}
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\item Introduces conditionals, loops, and other simple programmatic directives
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\item Used to speed model development
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\item Useful in various situations
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\begin{itemize}
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\item Multi-country models
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\item Creation of modular \texttt{.mod} files
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\item Variable flipping
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\item Conditional inclusion of equations
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\item ...among others
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\end{itemize}
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\end{itemize}
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\end{itemize}
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\end{frame}
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\begin{frame}
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\frametitle{Design of the macro language}
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\begin{itemize}
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\item The Dynare macro language provides a new set of \textbf{macro commands} that can be used in \texttt{.mod} files
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\item The macro processor transforms a \texttt{.mod} file with macro commands into a \texttt{.mod} file without macro commands (doing text expansions/inclusions) and then feeds it to the Dynare parser
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\item The key point to understand is that the macro processor only does \textbf{text substitution} (like the C preprocessor or the PHP language)
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\end{itemize}
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\end{frame}
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\begin{frame}
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\frametitle{Dynare Flowchart}
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\includegraphics[width=0.95\linewidth]{new-design.pdf}
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\end{frame}
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\section{Syntax}
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\begin{frame}[fragile=singleslide]
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\frametitle{Macro Directives}
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\begin{itemize}
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\item Directives begin with:\verb+@#+
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\item A directive gives instructions to the macro processor
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\item Main directives are:
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\begin{itemize}
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\item file inclusion: \verb+@#include+
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\item definition of a macro processor variable: \verb+@#define+
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\item conditional statements: \verb+@#if/@#ifdef/@#ifndef/@#else/@#endif+
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\item loop statements: \verb+@#for/@#endfor+
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\end{itemize}
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\item Most directives fit on one line. If needed however, two backslashes (i.e. \verb+\\+) at the end of a line indicate that the directive is continued on the next line.
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\end{itemize}
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\end{frame}
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\begin{frame}
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\frametitle{Variables}
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\begin{itemize}
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\item The macro processor has its own list of variables which are different than model variables and MATLAB/Octave variables
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\item There are 6 types of macro-variables:
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\begin{itemize}
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\item boolean
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\item double
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\item string
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\item tuple
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\item array
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\item function
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\end{itemize}
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\end{itemize}
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\end{frame}
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\begin{frame}[fragile=singleslide]
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\frametitle{Macro-expressions (1/8)}
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\begin{itemize}
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\item Macro-expressions are constructed using literals of the 6 basic types
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described above, macro-variables, comprehensions, and standard operators.
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\item Macro-expressions can be used in two places:
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\begin{itemize}
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\item inside macro directives; no special markup is required
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\item in the body of the \texttt{.mod} file, between an at sign and curly braces (like \verb+@{expr}+); the macro processor will substitute the expression with its value
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\end{itemize}
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\end{itemize}
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\end{frame}
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\begin{frame}[fragile=singleslide]
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\frametitle{Macro-expressions (2/8): Boolean}
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It is possible to construct macro-expressions using standard operators.
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\begin{block}{Operators on booleans}
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\begin{itemize}
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\item comparison operators: \texttt{== !=}
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\item logical operators: \verb+&& || !+
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\end{itemize}
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\end{block}
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\end{frame}
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\begin{frame}[fragile=singleslide]
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\frametitle{Macro-expressions (3/8): Double}
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\begin{block}{Operators on doubles}
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\begin{itemize}
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\item arithmetic operators: \texttt{+ - * / \^{}}
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\item comparison operators: \texttt{< > <= >= == !=}
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\item logical operators: \verb+&& || !+
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\item integer ranges: \texttt{1:4} is equivalent to integer array \texttt{[1,2,3,4]}. NB \texttt{[1:4]} is equivalent to an array containing one integer array \texttt{[[1,2,3,4]]}
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\end{itemize}
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\end{block}
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\begin{block}{Functions for doubles}
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\begin{itemize}
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\item \texttt{min, max, exp, ln (or log), log10}
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\item \texttt{sin, cos, tan, asin, acos, atan}
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\item \texttt{sqrt, cbrt, sign, floor, ceil, trunc, mod}
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\item \texttt{erf, erfc, normpdf, normcdf, gamma, lgamma, round}
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\end{itemize}
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\end{block}
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\end{frame}
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\begin{frame}[fragile=singleslide]
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\frametitle{Macro-expressions (4/8): String}
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String literals have to be declared between \textit{double} quotes, e.g. \texttt{``string''}
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\begin{block}{Operators on character strings}
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\begin{itemize}
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\item comparison operators: \texttt{< > <= >= == !=}
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\item concatenation: \texttt{+}
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\item string length: \texttt{length()}
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\item extraction of substrings: if \texttt{s} is a string, then one can write \texttt{s[3]} or \texttt{s[4:6]}
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\end{itemize}
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\end{block}
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\end{frame}
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\begin{frame}[fragile=singleslide]
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\frametitle{Macro-expressions (5/8): Tuple}
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Tuples are enclosed by parenthesis and elements separated by commas (like
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\texttt{(a,b,c)} or \texttt{(1,2.2,c)}).
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\begin{block}{Operators on tuples}
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\begin{itemize}
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\item comparison operators: \texttt{== !=}
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\item functions: \texttt{length, empty}
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\item testing membership in tuple: \texttt{in} operator \\ (example:
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\texttt{"b" in ("a", "b", "c")} returns \texttt{1})
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\end{itemize}
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\end{block}
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\end{frame}
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\begin{frame}[fragile=singleslide]
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\frametitle{Macro-expressions (6/8): Array}
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Arrays are enclosed by brackets, and their elements are separated by commas
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(like \texttt{[1,[2,3],4]} or \texttt{[``US'', ``EA'']}).
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\begin{block}{Operators on arrays}
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\begin{itemize}
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\item comparison operators: \texttt{== !=}
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\item dereferencing: if \texttt{v} is an array, then \texttt{v[2]} is its $2^{\textrm{nd}}$ element
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\item concatenation: \texttt{+}
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\item functions: \texttt{sum, length, empty}
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\item difference \texttt{-}: returns the first operand from which the elements of the second operand have been removed
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\item Cartesian product of two arrays: \texttt{*}
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\item Cartesian product of one array \texttt{N} times: \texttt{\^{}N}
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\item extraction of sub-arrays: \textit{e.g.} \texttt{v[4:6]}
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\item testing membership of an array: \texttt{in} operator \\ (example:
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\texttt{"b" in ["a", "b", "c"]} returns \texttt{1})
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\end{itemize}
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\end{block}
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\end{frame}
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\begin{frame}[fragile=singleslide]
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\frametitle{Macro-expressions (7/8): Comprehension (1/3)}
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Comprehensions are a shorthand way of creating arrays from other arrays. This is done by filtering, mapping, or filtering and mapping
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\begin{block}{Filtering}
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\begin{itemize}
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\item Allows one to choose those elements from an array for which a condition holds
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\item Syntax: \texttt{[variable/tuple IN array WHEN condition]}
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\item Example: Choose even numbers from array
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\begin{itemize}
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\item Code: \texttt{@\{[ i in 1:5 when mod(i,2) == 0 ]\}}
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\item Result: \texttt{[2, 4]}
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\end{itemize}
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\end{itemize}
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\end{block}
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\end{frame}
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\begin{frame}[fragile=singleslide]
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\frametitle{Macro-expressions (7/8): Comprehension (2/3)}
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\begin{block}{Mapping}
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\begin{itemize}
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\item Allows one to apply a transformation to every element of an array
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\item Syntax: \texttt{[expr for variable/tuple IN array]}
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\item Example: Square elements in array
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\begin{itemize}
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\item Code: \texttt{@\{[ i\^{}2 for i in 1:5 ]\}}
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\item Result: \texttt{[1, 4, 9, 16, 25]}
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\end{itemize}
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\item Example: Reverse order of elements in array
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\begin{itemize}
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\item Code: \texttt{@\{[ (j,i) for (i,j) in (1:2)\^{}2 ]\}}
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\item Result: \texttt{[(1, 1), (2, 1), (1, 2), (2, 2)]}
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\end{itemize}
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\end{itemize}
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\end{block}
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\end{frame}
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\begin{frame}[fragile=singleslide]
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\frametitle{Macro-expressions (7/8): Comprehension (3/3)}
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\begin{block}{Mapping and Filtering}
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\begin{itemize}
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\item Allows one to apply a transformation to the elements selected from an array
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\item Syntax: \texttt{[expr for variable/tuple IN array WHEN condition]}
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\item Example: Square odd numbers from array
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\begin{itemize}
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\item Code: \texttt{@\{[ i\^{}2 for i in 1:5 when mod(i,2) == 1 ]\}}
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\item Result: \texttt{[1, 9, 25]}
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\end{itemize}
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\end{itemize}
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\end{block}
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\end{frame}
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\begin{frame}[fragile=singleslide]
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\frametitle{Macro-expressions (8/8): Functions}
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\begin{itemize}
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\item Can take any number of arguments
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\item Dynamic binding: is evaluated when invoked, not when defined
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\item Can be included in expressions; valid operators depend on return type
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\end{itemize}
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\end{frame}
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\begin{frame}[fragile=singleslide]
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\frametitle{Define directive}
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The value of a macro-variable can be defined with the \verb+@#define+ directive.
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\begin{block}{Syntax}
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\verb+@#define +\textit{variable\_name}\verb+ = +\textit{expression}
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\end{block}
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\begin{block}{Examples}
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\begin{verbatim}
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@#define x = 5 // Integer
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@#define y = "US" // String
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@#define v = [ 1, 2, 4 ] // Integer array
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@#define w = [ "US", "EA" ] // String array
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@#define z = 3 + v[2] // Equals 5
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@#define t = ("US" in w) // Equals 1 (true)
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@#define f(x) = " " + x + y // Function f with argument x
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\end{verbatim}
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\end{block}
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NB: You can define macro variables on the dynare command line by using the \texttt{-D} option
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\end{frame}
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\begin{frame}[fragile=singleslide]
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\frametitle{Expression substitution}
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\framesubtitle{Dummy example}
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\begin{block}{Before macro processing}
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\begin{verbatim}
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@#define x = 1
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@#define y = [ "B", "C" ]
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@#define i = 2
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@#define f(x) = x + " + " + y[i]
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@#define i = 1
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model;
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A = @{y[i] + f("D")};
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end;
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\end{verbatim}
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\end{block}
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\begin{block}{After macro processing}
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\begin{verbatim}
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model;
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A = BD + B;
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end;
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\end{verbatim}
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\end{block}
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\end{frame}
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\begin{frame}[fragile=singleslide]
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\frametitle{Include directive (1/2)}
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\begin{itemize}
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\item This directive simply inserts the text of another file in its place
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\begin{block}{Syntax}
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\verb+@#include "+\textit{filename}\verb+"+
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\end{block}
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\begin{block}{Example}
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\begin{verbatim}
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@#include "modelcomponent.mod"
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\end{verbatim}
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\end{block}
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\item Equivalent to a copy/paste of the content of the included file
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\item Note that it is possible to nest includes (\textit{i.e.} to include a
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file with an included file)
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\end{itemize}
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\end{frame}
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\begin{frame}[fragile=singleslide]
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\frametitle{Include directive (2/2)}
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\begin{itemize}
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\item The filename can be given by a macro-variable (useful in loops):
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\begin{block}{Example with variable}
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\begin{verbatim}
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@#define fname = "modelcomponent.mod"
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@#include fname
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\end{verbatim}
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\end{block}
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\item Files to include are searched for in the current directory. Other directories can
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be added with the
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\verb+@#includepath+ directive, the \texttt{-I} command line option, or the
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\texttt{[paths]} section in config file.
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\end{itemize}
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\end{frame}
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\begin{frame}[fragile=singleslide]
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\frametitle{Loop directive}
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\begin{block}{Syntax}
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\verb+@#for +\textit{variable\_name}\verb+ in +\textit{array\_expr} \\
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\verb+ +\textit{loop\_body} \\
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\verb+@#endfor+
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\end{block}
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\begin{block}{Example: before macro processing}
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\small
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\begin{verbatim}
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model;
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@#for country in [ "home", "foreign" ]
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GDP_@{country} = A * K_@{country}^a * L_@{country}^(1-a);
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@#endfor
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end;
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\end{verbatim}
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\normalsize
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\end{block}
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\begin{block}{Example: after macro processing}
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\small
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\begin{verbatim}
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model;
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GDP_home = A * K_home^a * L_home^(1-a);
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GDP_foreign = A * K_foreign^a * L_foreign^(1-a);
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end;
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\end{verbatim}
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\normalsize
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\end{block}
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\end{frame}
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\begin{frame}[fragile=singleslide]
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\frametitle{Conditional directives (1/2)}
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\begin{columns}[T]
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\column{0.47\linewidth}
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\begin{block}{Syntax 1}
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\verb+@#if +\textit{integer\_expr} \\
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\verb+ +\textit{body included if expr != 0} \\
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\verb+@#endif+
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\end{block}
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\column{0.47\linewidth}
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\begin{block}{Syntax 2}
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\verb+@#if +\textit{integer\_expr} \\
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\verb+ +\textit{body included if expr != 0} \\
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\verb+@#else+ \\
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\verb+ +\textit{body included if expr == 0} \\
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\verb+@#endif+
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\end{block}
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\end{columns}
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\begin{block}{Example: alternative monetary policy rules}
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\scriptsize
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\begin{verbatim}
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@#define linear_mon_pol = 0 // or 1
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...
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model;
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@#if linear_mon_pol
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i = w*i(-1) + (1-w)*i_ss + w2*(pie-piestar);
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@#else
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i = i(-1)^w * i_ss^(1-w) * (pie/piestar)^w2;
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@#endif
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...
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end;
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\end{verbatim}
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\scriptsize
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\end{block}
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\end{frame}
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\begin{frame}[fragile=singleslide]
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\frametitle{Conditional directives (2/2)}
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|
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\begin{columns}[T]
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\column{0.47\linewidth}
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\begin{block}{Syntax 1}
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\verb+@#ifdef +\textit{variable\_name} \\
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\verb+ +\textit{body included if variable defined} \\
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\verb+@#endif+
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\end{block}
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\column{0.47\linewidth}
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\begin{block}{Syntax 2}
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\verb+@#ifdef +\textit{variable\_name} \\
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\verb+ +\textit{body included if variable defined} \\
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\verb+@#else+ \\
|
|
\verb+ +\textit{body included if variable not defined} \\
|
|
\verb+@#endif+
|
|
\end{block}
|
|
\end{columns}
|
|
|
|
\bigskip
|
|
|
|
There is also \verb+@#ifndef+, which is the opposite of \verb+@#ifdef+
|
|
(\textit{i.e.} it tests whether a variable is \emph{not} defined).
|
|
\end{frame}
|
|
|
|
\begin{frame}[fragile=singleslide]
|
|
\frametitle{Echo and error directives}
|
|
|
|
\begin{itemize}
|
|
\item The echo directive will simply display a message on standard output
|
|
\item The error directive will display the message and make Dynare stop (only makes sense inside a conditional directive)
|
|
\item The echomacrovars directive will display all of the macro variables and their values
|
|
\end{itemize}
|
|
|
|
\begin{block}{Syntax}
|
|
\verb+@#echo +\textit{string\_expr} \\
|
|
\verb+@#error +\textit{string\_expr} \\
|
|
\verb+@#echomacrovars +
|
|
\end{block}
|
|
|
|
\begin{block}{Examples}
|
|
\begin{verbatim}
|
|
@#echo "Information message."
|
|
@#error "Error message!"
|
|
\end{verbatim}
|
|
\end{block}
|
|
\end{frame}
|
|
|
|
\begin{frame}
|
|
\frametitle{Macro-related command line options}
|
|
\begin{itemize}
|
|
\item \texttt{savemacro}: Useful for debugging or learning purposes, saves the output of the macro processor. If your \texttt{.mod} file is called \texttt{file.mod}, the output is saved to \texttt{file-macroexp.mod}.
|
|
\item \texttt{nolinemacro}: In the output of \texttt{savemacro}, don't print line numbers where the macro directives were placed.
|
|
\item \texttt{noemptylinemacro}: Remove empty lines in the output of \texttt{savemacro}.
|
|
\item \texttt{onlymacro}: Stops processing after the macro processing step.
|
|
\end{itemize}
|
|
\end{frame}
|
|
|
|
\section{Common uses}
|
|
|
|
\begin{frame}[fragile=singleslide]
|
|
\frametitle{Modularization}
|
|
\begin{itemize}
|
|
\item The \verb+@#include+ directive can be used to split \texttt{.mod} files into several modular components
|
|
\item Example setup:
|
|
\begin{description}
|
|
\item[\texttt{modeldesc.mod}:] contains variable declarations, model equations and shocks declarations
|
|
\item[\texttt{simulate.mod}:] includes \texttt{modeldesc.mod}, calibrates parameters and runs stochastic simulations
|
|
\item[\texttt{estim.mod}:] includes \texttt{modeldesc.mod}, declares priors on parameters and runs bayesian estimation
|
|
\end{description}
|
|
\item Dynare can be called on \texttt{simulate.mod} and \texttt{estim.mod}
|
|
\item But it makes no sense to run it on \texttt{modeldesc.mod}
|
|
\item Advantage: no need to manually copy/paste the whole model (at the beginning) or changes to the model (during development)
|
|
\end{itemize}
|
|
\end{frame}
|
|
|
|
\begin{frame}[fragile=singleslide]
|
|
\frametitle{Indexed sums or products}
|
|
\framesubtitle{Example: moving average}
|
|
\begin{columns}[T]
|
|
\column{0.47\linewidth}
|
|
\begin{block}{Before macro processing}
|
|
\begin{verbatim}
|
|
@#define window = 2
|
|
|
|
var x MA_x;
|
|
...
|
|
model;
|
|
...
|
|
MA_x = @{1/(2*window+1)}*(
|
|
@#for i in -window:window
|
|
+x(@{i})
|
|
@#endfor
|
|
);
|
|
...
|
|
end;
|
|
\end{verbatim}
|
|
\end{block}
|
|
\column{0.47\linewidth}
|
|
\begin{block}{After macro processing}
|
|
\begin{verbatim}
|
|
var x MA_x;
|
|
...
|
|
model;
|
|
...
|
|
MA_x = 1/5*(
|
|
+x(-2)
|
|
+x(-1)
|
|
+x(0)
|
|
+x(1)
|
|
+x(2)
|
|
);
|
|
...
|
|
end;
|
|
\end{verbatim}
|
|
\end{block}
|
|
\end{columns}
|
|
\end{frame}
|
|
|
|
\begin{frame}[fragile=singleslide]
|
|
\frametitle{Multi-country models}
|
|
\framesubtitle{\texttt{.mod} file skeleton example}
|
|
\scriptsize
|
|
\begin{verbatim}
|
|
@#define countries = [ "US", "EA", "AS", "JP", "RC" ]
|
|
@#define nth_co = "US"
|
|
|
|
@#for co in countries
|
|
var Y_@{co} K_@{co} L_@{co} i_@{co} E_@{co} ...;
|
|
parameters a_@{co} ...;
|
|
varexo ...;
|
|
@#endfor
|
|
|
|
model;
|
|
@#for co in countries
|
|
Y_@{co} = K_@{co}^a_@{co} * L_@{co}^(1-a_@{co});
|
|
...
|
|
@# if co != nth_co
|
|
(1+i_@{co}) = (1+i_@{nth_co}) * E_@{co}(+1) / E_@{co}; // UIP relation
|
|
@# else
|
|
E_@{co} = 1;
|
|
@# endif
|
|
@#endfor
|
|
end;
|
|
\end{verbatim}
|
|
\normalsize
|
|
\end{frame}
|
|
|
|
\begin{frame}
|
|
\frametitle{Endogeneizing parameters (1/4)}
|
|
\begin{itemize}
|
|
\item When calibrating the model it may be useful to consider a parameter as an endogenous (and vice-versa)
|
|
\item Example:
|
|
\begin{gather*}
|
|
y = \left(\alpha^{\frac{1}{\xi}} \ell^{1-\frac{1}{\xi}} + (1-\alpha)^{\frac{1}{\xi}}k^{1-\frac{1}{\xi}}\right)^{\frac{\xi}{\xi - 1}} \\
|
|
lab\_rat = \frac{w \ell}{p y}
|
|
\end{gather*}
|
|
\item In the model, $\alpha$ is a (share) parameter, and $lab\_rat$ is an endogenous variable
|
|
\item We observe that:
|
|
\begin{itemize}
|
|
\item calibrating $\alpha$ is not straigthforward!
|
|
\item on the contrary, we have real world data for $lab\_rat$
|
|
\item it is clear that these two variables are economically linked
|
|
\end{itemize}
|
|
\end{itemize}
|
|
\end{frame}
|
|
|
|
\begin{frame}[fragile=singleslide]
|
|
\frametitle{Endogeneizing parameters (2/4)}
|
|
\begin{itemize}
|
|
\item Therefore, when computing the steady state:
|
|
\begin{itemize}
|
|
\item we make $\alpha$ an endogenous variable and $lab\_rat$ a parameter
|
|
\item we impose an economically relevant value for $lab\_rat$
|
|
\item the solution algorithm deduces the implied value for $\alpha$
|
|
\end{itemize}
|
|
\item We call this method ``variable flipping''
|
|
\end{itemize}
|
|
\end{frame}
|
|
|
|
\begin{frame}[fragile=singleslide]
|
|
\frametitle{Endogeneizing parameters (3/4)}
|
|
\framesubtitle{Example implementation}
|
|
\begin{itemize}
|
|
\item File \texttt{modeqs.mod}:
|
|
\begin{itemize}
|
|
\item contains variable declarations and model equations
|
|
\item For declaration of \texttt{alpha} and \texttt{lab\_rat}:
|
|
\footnotesize
|
|
\begin{verbatim}
|
|
@#if steady
|
|
var alpha;
|
|
parameter lab_rat;
|
|
@#else
|
|
parameter alpha;
|
|
var lab_rat;
|
|
@#endif
|
|
\end{verbatim}
|
|
\normalsize
|
|
\end{itemize}
|
|
|
|
\end{itemize}
|
|
\end{frame}
|
|
|
|
\begin{frame}[fragile=singleslide]
|
|
\frametitle{Endogeneizing parameters (4/4)}
|
|
\framesubtitle{Example implementation}
|
|
\begin{itemize}
|
|
\item File \texttt{steadystate.mod}:
|
|
\begin{itemize}
|
|
\item begins with \verb+@#define steady = 1+
|
|
\item then with \verb+@#include "modeqs.mod"+
|
|
\item initializes parameters (including \texttt{lab\_rat}, excluding \texttt{alpha})
|
|
\item computes steady state (using guess values for endogenous, including \texttt{alpha})
|
|
\item saves values of parameters and endogenous at steady-state in a file, using the \texttt{save\_params\_and\_steady\_state} command
|
|
\end{itemize}
|
|
\item File \texttt{simulate.mod}:
|
|
\begin{itemize}
|
|
\item begins with \verb+@#define steady = 0+
|
|
\item then with \verb+@#include "modeqs.mod"+
|
|
\item loads values of parameters and endogenous at steady-state from file, using the \texttt{load\_params\_and\_steady\_state} command
|
|
\item computes simulations
|
|
\end{itemize}
|
|
\end{itemize}
|
|
\end{frame}
|
|
|
|
\begin{frame}[fragile=singleslide]
|
|
\frametitle{MATLAB/Octave loops vs macro processor loops (1/3)}
|
|
Suppose you have a model with a parameter $\rho$, and you want to make
|
|
simulations for three values: $\rho = 0.8, 0.9, 1$. There are
|
|
several ways of doing this:
|
|
\begin{block}{With a MATLAB/Octave loop}
|
|
\begin{verbatim}
|
|
rhos = [ 0.8, 0.9, 1];
|
|
for i = 1:length(rhos)
|
|
rho = rhos(i);
|
|
stoch_simul(order=1);
|
|
end
|
|
\end{verbatim}
|
|
\end{block}
|
|
\begin{itemize}
|
|
\item The loop is not unrolled
|
|
\item MATLAB/Octave manages the iterations
|
|
\end{itemize}
|
|
\end{frame}
|
|
|
|
\begin{frame}[fragile=singleslide]
|
|
\frametitle{MATLAB/Octave loops vs macro processor loops (2/3)}
|
|
\begin{block}{With a macro processor loop (case 1)}
|
|
\begin{verbatim}
|
|
rhos = [ 0.8, 0.9, 1];
|
|
@#for i in 1:3
|
|
rho = rhos(@{i});
|
|
stoch_simul(order=1);
|
|
@#endfor
|
|
\end{verbatim}
|
|
\end{block}
|
|
\begin{itemize}
|
|
\item Very similar to previous example
|
|
\item Loop is unrolled
|
|
\item Dynare macro processor manages the loop index but not the data array (\texttt{rhos})
|
|
\end{itemize}
|
|
\end{frame}
|
|
|
|
\begin{frame}[fragile=singleslide]
|
|
\frametitle{MATLAB/Octave loops vs macro processor loops (3/3)}
|
|
\begin{block}{With a macro processor loop (case 2)}
|
|
\begin{verbatim}
|
|
@#for rho_val in [ 0.8, 0.9, 1]
|
|
rho = @{rho_val};
|
|
stoch_simul(order=1);
|
|
@#endfor
|
|
\end{verbatim}
|
|
\end{block}
|
|
\begin{itemize}
|
|
\item Shorter syntax, since list of values directly given in the loop construct
|
|
\item NB: Array not stored as MATLAB/Octave variable, hence cannot be used in MATLAB/Octave
|
|
\end{itemize}
|
|
\end{frame}
|
|
|
|
% \begin{frame}[fragile=singleslide]
|
|
% \frametitle{Possible future developments}
|
|
% \begin{itemize}
|
|
% \item Find a nicer syntax for indexed sums/products
|
|
% \item Implement other control structures: \texttt{elsif}, \texttt{switch/case}, \texttt{while/until} loops
|
|
% \item Implement macro-functions (or templates), with a syntax like:
|
|
% \small
|
|
% \verb+@#define QUADRATIC_COST(x, x_ss, phi) = phi/2*(x/x_ss-1)^2+
|
|
% \normalsize
|
|
% \end{itemize}
|
|
% \end{frame}
|
|
|
|
\begin{frame}
|
|
\begin{center}
|
|
\vfill {\LARGE Thanks for your attention!} \vfill
|
|
{\LARGE Questions?}
|
|
\vfill
|
|
\end{center}
|
|
\vfill
|
|
\end{frame}
|
|
|
|
|
|
\end{document}
|