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= Dynare with Octave =

Dynare is now able to run on GNU Octave, which is basically a free clone of MATLAB.

Octave versions ranging from 3.2.2 to 3.6 are supported (the unstable version requires 3.4 at least).

== About Octave ==

GNU Octave is a free clone of MATLAB, running under GNU/Linux, Windows and MacOS.

It normally runs in a command window, and displays graphics in separate windows (using Gnuplot).

Some ressources:

 * [[http://www.octave.org|Octave official site]]
 * [[http://octave.sourceforge.net|Octave Forge]]: a set of extensions for Octave
 * Official [[http://www.gnu.org/software/octave/doc/interpreter/|Octave manual]] online
 * A graphical frontend to Octave: [[http://qtoctave.wordpress.com/|QtOctave]]
 * On the compatibility between Octave and Matlab:
   * List of [[http://www.gnu.org/software/octave/FAQ.html#MATLAB-compatibility|differences between Octave and Matlab]]
   * List of [[http://wiki.octave.org/wiki.pl?MissingMatlabFunctions|missing Matlab functions]] in Octave
   * More on [[http://wiki.octave.org/wiki.pl?MatlabOctaveCompatibility|Matlab/Octave compatibility]]
 * Octave tutorials:
   * [[http://en.wikibooks.org/wiki/Octave_Programming_Tutorial|Octave Programming Tutorial]] on Wiki``Books
   * [[http://www8.cs.umu.se/~fotios/OctaveRevPack.pdf|GNU Octave/MATLAB revision pack]]

== Installing Dynare 4.3 with Octave ==

=== Windows (without Cygwin) ===

This is the recommended way for Windows users.

 * Download and install [[http://www.dynare.org/octave/Octave3.6.1_gcc4.6.2_20120303-setup.exe|Octave 3.6.1 (MinGW)]].
 * Download and install the latest Dynare package for Windows, see [[http://www.dynare.org/download/dynare-4.3/windows]].

=== Windows (with Cygwin) ===

 * Download and uncompress Dynare 4.3 sources from [[http://www.dynare.org/download/dynare-4.3/source]]
 * Follow the instructions for Cygwin on BuildingDynareFromSource.

Note that graphics are not supported when Octave is run from the Cygwin prompt; you need to use the option {{{nograph}}} in your MOD file. If you want graphics, install the X windows server.

=== GNU/Linux ===

For Debian or Ubuntu distributions, see InstallOnDebianOrUbuntu.

For other distributions:
 * install the package for Octave from your distribution
 * download and uncompress Dynare 4.3 sources from [[http://www.dynare.org/download/dynare-4.3/source]]
 * follow the instructions on BuildingDynareFromSource

== Running Dynare with Octave ==

First, you should run Octave.

Under GNU/Linux, at the prompt, just type:
{{{
octave
}}}
Under Windows, you should have a shortcut already installed in your Start menu.

It is also possible to run [[http://www.gnu.org/software/octave/doc/interpreter/Emacs.html|Octave under Emacs]].

Then, from Octave, add the path to Dynare with the {{{addpath}}} command, as you would under MATLAB:
{{{
addpath REPLACE_WITH_INSTALL_PATH/matlab
}}}
It is possible to autoexecute this command at each Octave start by adding it to the {{{.octaverc}}} startup file (under Linux, this file should be put in the home directory; under Windows, it should be put at the root of the user home under {{{Documents and Settings}}}).

=== Invoking Dynare ===

If your MOD file is {{{ramst.mod}}}, just type:
{{{
dynare ramst
}}}

== Current status of Dynare with Octave ==
= Current status of Dynare with Octave =
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== Main differences between MATLAB and Octave which are dealt with by Dynare == = Main differences between MATLAB and Octave which are dealt with by Dynare =

Current status of Dynare with Octave

  • Deterministic simulation works (tested on ramst.mod)

  • Stochastic simulation works (tested on example1.mod)

  • Bayesian estimation works (tested on arima/mod1a.mod).

    • However, Excel data files are not supported by Octave. A workaround is to convert the file to a text format (more details to come shortly)
  • Ramsey policy works
  • Results are saved in .mat files which can be read from MATLAB and from Octave

  • Graphics display:
    • basically works
    • however window titles ("Priors", ...) don't show up (with GNUplot backend)
    • the scale is sometimes ugly (overlapping characters) (with GNUplot backend)
    • warnings about missing font file show up (with GNUplot backend)
    • graphics are vertically shrinked when several plots are on the same window (with JHandles backend)
    • graphics saving on filesystem works for EPS, but not for PDF and FIG formats
    • currently, Dynare crashes when Octave is run without graphical capabilities; a workaround is to use option "nograph"

Main differences between MATLAB and Octave which are dealt with by Dynare

  • Generalized eigenvalues: eig(A,B) doesn't exist in Octave. A call to lambda = qz(A,B) does the same job, except that it doesn't return infinite eigenvalues, so we can't use it. Implied a change in dr1.m

  • QZ decomposition: [AA,BB,Q,Z] = qz(A,B) works under Octave, but:

    • the convention for Q is different. We have AA = Q*A*Z under Matlab and AA = Q'*A*Z under Octave. Implied a change in gensylv/sylvester3.m

    • Octave is only able to compute real QZ, while MATLAB can do both complex and real, and does complex by default. As a consequence, qz/mjdgges.m is implemented differently for Octave and MATLAB: under MATLAB we compute the complex decomposition, and use Sims' code for reordering the eigenvalues; under Octave, we use the native reordered QZ, but as a consequence the criterium is de facto always 1.0

  • Reciprocal condition number: rcond(A) doesn't exist under Octave. For the moment, the workaround is to create a rcond.m M-file which does 1/(norm(A,1)*norm(inv(A), 1)). The rcond() function is now available in Octave 3.2.

  • Saving data on the filesystem:

    • Octave can read and write Matlab's MAT format. A call to default_save_options('-mat') was added in dynare.m to make Dynare for Octave create MAT files

    • But save() and load() under Octave don't assume the .mat extension. Need to explicitly add them

  • Saving graphics on the filesystem:

    • Saving graphics with saveas() don't work, since it uses a Matlab specific format

    • Creation of PDF files is not supported (through print -dpdf). This comes from the fact that PDF support in GNUPlot is non-free, and therefore not available under Debian/Ubuntu or Windows package. See Debian bug #248426

    • Creation of EPS files works (though file extension is not automatically added by Octave, contrary to Matlab)
  • Warning handling is different between Matlab and Octave, and necessitated some adjustments

  • Adjustments were obviously necessary where version() function is called

  • The operator & under MATLAB is buggy: it doesn't execute its second argument if the first is false, when used in an if statement. This behaviour should be restricted to &&. This also applies to | and ||. Implied a change in mh_optimal_bandwith.m, since this file expects the buggy behaviour

  • waitbar() exists under Octave, but is text-only and is not very flexible. Replaced by calls to printf() in random_walk_metropolis_hastings.m

  • mkdir() works slightly differently under Octave: it won't simultaneously create several depths of subdirectories. Implied a change in CheckPath.m

  • setdiff() doesn't return a second argument under Octave. Implied a workaround in dynare_estimation.m and dynare_estimation_init.m

  • ordeig() doesn't exist under Octave (nor on MATLAB < 7.0.1). Use my_ordeig() instead.

  • Case sensitivity : under GNU/Linux, calls to Octave functions and variables are case sensitive. So non preprocessed instructions at the end of modfiles should be written with lowercase.

DynareWiki: OctaveCompatibility (last edited 2012-10-08 11:47:00 by SébastienVillemot)