Previous Page Next Page Contents

detools::autoreduce -- autoreduction of a system of differential equations

Introduction

detools::autoreduce autoreduces a system of differential equations, i.e. it tries to simplify the equations as much as possible by entering each equation into all the other ones. The ultimate goal is to achieve a triangular form.

Call(s)

detools::autoreduce(sys, indl, depl)
detools::autoreduce(dfs)

Parameters

sys - the differential equations: a list ofexpressions.
indl - the independent variables: a list of (indexed) identifiers.
depl - the dependent variables: a list of (indexed) identifiers.
dfs - the differential equations: a list of elements of a domain in Cat::DifferentialFunction(DV).

Returns

an autoreduced list of differential equations; the equations are represented either as expressions (first form of call) or as elements of a domain in Cat::DifferentialFunction(DV) (second form of call).

Related Functions

simplify

Details

Example 1

We want to simplify the two differential equations 3*diff(u(x,y),x,y)+diff(u(x,y),y)=0 and diff(u(x,y),x)=0. Obviously, the second order term in the first equation is a derivative of the second equation. Thus it is eliminated by detools::autoreduce.

>> detools::autoreduce([3*u([x, y]) + u([y]), u([x])], [x, y], [u])
                             [u([x]), u([y])]




Do you have questions or comments?


Copyright © SciFace Software GmbH & Co. KG 2000