# HG changeset patch # User jwe # Date 1181681507 0 # Node ID b55d109ffe7e61a61fdd2a1816151cda4c1c1323 # Parent 3f4ccca056124f14ab541141cf29eeb2bc6a54ca [project @ 2007-06-12 20:51:47 by jwe] diff -r 3f4ccca05612 -r b55d109ffe7e doc/ChangeLog --- a/doc/ChangeLog Tue Jun 12 20:48:03 2007 +0000 +++ b/doc/ChangeLog Tue Jun 12 20:51:47 2007 +0000 @@ -1,3 +1,7 @@ +2007-06-12 2007-06-10 Søren Hauberg + + * interpreter/diffeq.txi: Note that x-dot is the derivative of x. + 2007-06-03 David Bateman * interpreter/dynamic.txi: Use "mwSize" and "mwIndex" rather than diff -r 3f4ccca05612 -r b55d109ffe7e doc/interpreter/diffeq.txi --- a/doc/interpreter/diffeq.txi Tue Jun 12 20:48:03 2007 +0000 +++ b/doc/interpreter/diffeq.txi Tue Jun 12 20:51:47 2007 +0000 @@ -5,8 +5,9 @@ @node Differential Equations @chapter Differential Equations -Octave has two built-in functions for solving differential equations. -Both are based on reliable ODE solvers written in Fortran. +Octave has built-in functions for solving ordinary differential equations, +and differential-algebraic equations. +All solvers are based on reliable ODE solvers written in Fortran. @menu * Ordinary Differential Equations:: @@ -40,6 +41,8 @@ @noindent using Hindmarsh's ODE solver @sc{Lsode}. + + @DOCSTRING(lsode) @DOCSTRING(lsode_options) @@ -102,15 +105,25 @@ $$ @end tex @end iftex -@ifinfo +@ifnottex @example 0 = f (x-dot, x, t), x(t=0) = x_0, x-dot(t=0) = x-dot_0 @end example -@end ifinfo +@end ifnottex @noindent -using Petzold's DAE solver @sc{Daspk}. +where +@iftex +@tex +$\dot{x} = {dx \over dt}$ +@end tex +@end iftex +@ifnottex +@math{x-dot} +@end ifnottex +is the derivative of @math{x}. The equation is solved using Petzold's +DAE solver @sc{Daspk}. @DOCSTRING(daspk)