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diff NEWS-3.html @ 94:e8fc61e077fc
Merged closed branch "kai" into default.
| author | Kai T. Ohlhus <k.ohlhus@gmail.com> |
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| date | Tue, 01 Nov 2016 01:06:10 +0100 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/NEWS-3.html Tue Nov 01 01:06:10 2016 +0100 @@ -0,0 +1,222 @@ +<!doctype html public "-//IETF//DTD HTML Strict//EN"> +<html> +<head> +<title>Notable Changes in Octave version 3</title> +<link rel="stylesheet" type="text/css" href="octave.css" /> +</head> + +<body> +<div id="title"><h1>News for Octave Version 3</h1></div> + +<ul> +<li>Compatibility with Matlab graphics is much better. We now + have some graphics features that work like Matlab's Handle + Graphics (tm): +<ul> +<li> You can make a subplot and then use the print function to + generate file with the plot.</li> + +<li> RGB line colors are supported if you use gnuplot 4.2. Octave + can still use gnuplot 4.0, but there is no way to set arbitrary + line colors with it when using the Matlab-style plot functions. + There never was any way to do this reliably with older versions + of gnuplot (whether run from Octave or not) since it only + provided a limited set to choose from, and they were terminal + dependent, so choosing color 1 with the X11 terminal would be + different from color 1 with the PostScript terminal. Valid RGB + colors for gnuplot 4.0 are the eight possible combinations of 0 + and 1 for the R, G and B values. Invalid values are all mapped + to the same color. +<p> + This also affects patch objects used in the bar, countour, meshc + and surfc functions, where the bars and contours will be + monochrome. A workaround for this is to type "colormap gmap40" + that loads a colormap that in many cases will be adequate for + simple bar and contour plots.</li> + +<li> You can control the width of lines using (for example): +<pre> + line (x, y, "linewidth", 4, "color", [1, 0, 0.5]); +</pre> + (this also shows the color feature).</li> + +<li> With gnuplot 4.2, image data is plotted with gnuplot and may be + combined with other 2-d plot data.</li> + +<li> Lines for contour plots are generated with an Octave function, so + contour plots are now 2-d plots instead of special 3-d plots, and + this allows you to plot additional 2-d data on top of a contour + plot.</li> + +<li> With the gnuplot "extended" terminals the TeX interpreter is + emulated. However, this means that the TeX interpreter is only + supported on the postscript terminals with gnuplot 4.0. Under + gnuplot 4.2 the terminals aqua, dumb, png, jpeg, gif, pm, windows, + wxt, svg and x11 are supported as well.</li> + +<li> The following plot commands are now considered obsolete and will + be removed from a future version of Octave: +<pre> + __gnuplot_set__ + __gnuplot_show__ + __gnuplot_plot__ + __gnuplot_splot__ + __gnuplot_replot__ +</pre> + Additionally, these functions no longer have any effect on plots + created with the Matlab-style plot commands + (<tt>plot</tt>, <tt>line</tt>, <tt>mesh</tt>, <tt>semilogx</tt>, + etc.). + +<li> Plot property values are not extensively checked. Specifying + invalid property values may produce unpredictible results.</li> + +<li> Octave now sends data over the same pipe that is used to send + commands to gnuplot. While this avoids the problem of + cluttering /tmp with data files, it is no longer possible to use + the mouse to zoom in on plots. This is a limitation of gnuplot, + which is unable to zoom when the data it plots is not stored in + a file. Some work has been done to fix this problem in newer + versions of gnuplot (> 4.2.2). See for example, + <a href="http://www.nabble.com/zooming-of-inline-data-tf4357017.html#a12416496">this thread</a> on the gnuplot development list. +</ul></li> + + +<li>The way Octave handles search paths has changed. Instead of + setting the built-in variable <tt>LOADPATH</tt>, you must + use <tt>addpath</tt>, <tt>rmpath</tt>, or <tt>path</tt> to + manipulate the function search path. These functions will + maintain <tt>"."</tt> at the head of the path, for compatibility + with Matlab. +<p> + Leading, trailing or doubled colons are no longer special. + Now, all elements of the search path are explicitly included in + the path when Octave starts. To display the path, use + the <tt>path</tt> function. +<p> + Path elements that end in <tt>//</tt> are no longer searched recursively. + Instead, you may use addpath and the genpath function to add an + entire directory tree to the path. For example, +<pre> + addpath (genpath ("~/octave")); +</pre> + will add ~/octave and all directories below it to the head of the + path.</li> + + +<li>Previous versions of Octave had a number of built-in variables to + control warnings (for example, <tt>warn_divide_by_zero</tt>). These + variables have been replaced by warning identifiers that are used + with the warning function to control the state of warnings. +<p> + For example, instead of writing +<pre> + warn_divide_by_zero = false; +</pre> + to disable divide-by-zero warnings, you should write +<pre> + warning ("off", "Octave:divide-by-zero"); +</pre> + You may use the same technique in your own code to control + warnings. For example, you can use +<pre> + warning ("My-package:phase-of-the-moon", + "the phase of the moon could cause trouble today"); +</pre> + to allow users to control this warning using the + <tt>"My-package:phase-of-the-moon"</tt> warning identifier. +<p> + You may also enable or disable all warnings, or turn them into + errors: +<pre> + warning ("on", "all"); + warning ("off", "all"); + warning ("error", "Octave:divide-by-zero"); + warning ("error", "all"); +</pre> + You can query the state of current warnings using +<pre> + warning ("query", ID) + warning ("query") +</pre> + (only those warning IDs which have been explicitly set are + returned). +<p> + A partial list and description of warning identifiers is available + using +<pre> + help warning_ids +</pre></li> + + +<li>All built-in variables have been converted to functions. This + change simplifies the interpreter and allows a consistent + interface to internal variables for user-defined packages and the + core functions distributed with Octave. In most cases, code that + simply accesses internal variables does not need to change. Code + that sets internal variables will change. For example, instead of + writing +<pre> + PS1 = ">> "; +</pre> + you will need to write +<pre> + PS1 (">> "); +</pre> + If you need write code that will run in both old and new versions + of Octave, you can use something like +<pre> + if (exist ("OCTAVE_VERSION") == 5) + ## New: + PS1 (">> "); + else + ## Old: + PS1 = ">> "; + endif +</pre></li> + + +<li>For compatibility with Matlab, the output order of Octave's + <tt>"system"</tt> function has changed from +<pre> + [output, status] = system (cmd); +</pre> + to +<pre> + [status, output] = system (cmd); +</pre></li> + + +<li>For compatibility with Matlab, <tt>normcdf</tt>, <tt>norminv</tt>, + <tt>normpdf</tt>, and <tt>normrnd</tt> have been modified to + compute distributions using the standard deviation instead of the + variance.</li> + + +<li>For compatibility with Matlab, the output of Octave's fsolve + function has been changed from +<pre> + [x, info, msg] = fsolve (...); +</pre> + to +<pre> + [x, fval, info] = fsolve (...); +</pre></li> + + +<li>For compatibility with Matlab, <tt>normcdf</tt>, <tt>norminv</tt>, + <tt>normpdf</tt>, and <tt>normrnd</tt> have been modified to + compute distributions using the standard deviation instead of the + variance.</li> + + +<li>For compatibility with + Matlab, <tt>gamcdf</tt>, <tt>gaminv</tt>, <tt>gampdf</tt>, + <tt>gamrnd</tt>, <tt>expcdf</tt>, <tt>expinv</tt>, <tt>exppdf</tt> + and <tt>exprnd</tt> have been modified to compute the + distributions using the standard scale factor rather than one over + the scale factor. +</ul> + +</body> +</html>