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| *[http://ltilib.sourceforge.net/doc/homepage/index.shtml LTI-Lib] is an object oriented library with algorithms and data structures frequently used in image processing and computer vision. LGPL | | *[http://ltilib.sourceforge.net/doc/homepage/index.shtml LTI-Lib] is an object oriented library with algorithms and data structures frequently used in image processing and computer vision. LGPL |
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| ==Symbolic==
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| ===Symbolic Manipulation===
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| Octave is a matrix algebra tool, not a symbolic algebra tool, so it cannot perform symbolic operations, such as finding the derivative of sine(x) with respect to x
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| y = derivative('sin(x)','x'); # Not available in Octave
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| The below mentioned GiNaC will add symbolic functionality to octave.
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| ===Octave interfaces to GiNaC===
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| There are two Octave interfaces to GiNaC[1] available
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| *gino -- http://www.sourceforge.net/projects/mtt (download) provides an Octave interface to GiNaC via ginsh
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| octave:1> df = g_diff ( "sin(x)" , "x" )
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| df = cos(x)
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| octave:2> x = pi; eval ( df );
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| ans = -1
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| *OctaveForge provides direct access to GiNaC in the [http://octave.sourceforge.net/index/navsymbolic.html symbolic package]. Here is a http://wiki.octave.org/wiki.pl?OctaveForgeGNCIntro short tutorial] to get you started.
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| ===Numerical methods===
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| In some instances, Octave can give reasonable results using numerical methods
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| *Octave supports numerical derivatives:
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| t = linspace(0,6,100);
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| y = sin(t);
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| dydt = diff(y) ./ diff(t)
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| *OctaveForge has other numerical derivative functions.
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| ===Symbolic algebra systems===
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| Software other than Octave may be more useful for work involving symbolic manipulations
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| Free software
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| *Axiom: http://www.nongnu.org/axiom/
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| *GiNaC/ginsh: http://www.ginac.de
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| *Maxima: http://maxima.sourceforge.net
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| *Yacas: http://yacas.sourceforge.net
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| Non-free software
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| *Maple: http://www.maplesoft.com
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| *Reduce: http://www.uni-koeln.de/REDUCE
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| Note that most of these systems (and Octave!) may be used from within TeXmacs http://www.texmacs.org
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| A list of some other scientific software is available at http://sal.kachinatech.com/
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