lin

Arguments

sim

function

x0, u0

vectors of compatible dimensions

A,B,C,D

real matrices

sl

syslin list

Description

linearization of the non-linear system [y,xdot]=sim(x,u) around x0,u0.

sim is a function which computes y and xdot.

The output is a linear system (syslin list) sl or the four matrices (A,B,C,D)

For example, if ftz is the function passed to ode e.g.

[zd]=ftz(t,z,u)

and if we assume that y=x

[z]=ode(x0,t0,tf,list(ftz,u) compute x(tf).

If simula is the following function:

deff('[y,xd]=simula(x,u)','xd=ftz(tf,x,u); y=x;');

the tangent linear system sl can be obtained by:

[A,B,C,D]=lin(simula,z,u)
sl = syslin('c',A,B,C,D,x0)

Examples

deff('[y,xdot]=sim(x,u)','xdot=[u*sin(x);-u*x^2];y=xdot(1)+xdot(2)')
sl=lin(sim,1,2);

See also

• external — Objet Scilab, fonction externe ou routine
• derivat — dérivée de polynômes ou de fractions rationnelles