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author | dos-reis <gdr@axiomatics.org> | 2007-08-14 05:14:52 +0000 |
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committer | dos-reis <gdr@axiomatics.org> | 2007-08-14 05:14:52 +0000 |
commit | ab8cc85adde879fb963c94d15675783f2cf4b183 (patch) | |
tree | c202482327f474583b750b2c45dedfc4e4312b1d /src/input/ode.input.pamphlet | |
download | open-axiom-ab8cc85adde879fb963c94d15675783f2cf4b183.tar.gz |
Initial population.
Diffstat (limited to 'src/input/ode.input.pamphlet')
-rw-r--r-- | src/input/ode.input.pamphlet | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/src/input/ode.input.pamphlet b/src/input/ode.input.pamphlet new file mode 100644 index 00000000..703fd348 --- /dev/null +++ b/src/input/ode.input.pamphlet @@ -0,0 +1,60 @@ +\documentclass{article} +\usepackage{axiom} +\begin{document} +\title{\$SPAD/src/input ode.input} +\author{The Axiom Team} +\maketitle +\begin{abstract} +\end{abstract} +\eject +\tableofcontents +\eject +\section{License} +<<license>>= +--Copyright The Numerical Algorithms Group Limited 1996. +@ +<<*>>= +<<license>> + + +--A bug when one one uses a diff.eq. with a free variable other than x. +)set break resume +y:=operator 'y +deqx:= differentiate(y x,x,2)+differentiate(y x,x) +y x +solve(deqx,y,x) --OK +solve(deqx,y,x=0,[1]) --OK +deqt:= differentiate(y t,t,2)+differentiate(y t,t) +y t +solve(deqt,y,t) --OK +solve(deqt,y,t=0,[1]) -- BUG! +deqz:= differentiate(y z,z,2)+differentiate(y z,z) +y z +solve(deqz,y,z) --OK +solve(deqz,y,z=0,[1]) -- BUG! + + +--I think the bug is in +-- file odeef.spad +-- constructor ODEEF +-- function solve(diffeq:F,y:OP,center:EQ,y0:List F) + +--the second line of the body was + +-- kx:K:=kernel x + +--which uses uninitialised x. I think it should be + +-- kx:K:=kernel(retract(lhs(center))@SY) + +--as the line immediately below it. That change certainly fixes THIS bug! + +--Also, maybe a check should be made that this kx is indeed to be found +--in the diffeq -- my system reports segmenttion violation if I do + + +solve(deqt,y,x=0,[1]) + +@ +\eject +\begin{thebibliography}{99} +\bibitem{1} nothing +\end{thebibliography} +\end{document} |