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Aide Scilab >> Equations Differentielles > daeoptions

# daeoptions

set options for dae solver

### Calling Sequence

`daeoptions()`

### Description

If it exists in the dae function calling context the variable `%DAEOPTIONS` the dae function use it to sets options.

This daeoptions function interactively displays a command which should be executed to set various options of the dae solver.

CAUTION: the `dae` function checks if this variable exists and in this case it uses it. For using default values you should clear this variable. Note that `daeoptions` does not create this variable. To create it you must execute the command line displayed by `daeoptions`.

The variable `%DAEOPTIONS` is a list with the following elements:

`list(tstop,imode,band,maxstep,stepin,nonneg,isest)`

The default value is:

`list([],0,[],[],[],0,0)`

The meaning of the elements is described below.

tstop

a real scalar or an empty matrix, gives the maximum time for which `g`is allowed to be evaluated. An empty matrix means "no limits" imposed for time.

imode

if it is 0 dae returns only the user specified time point values if it is 1 dae returns its intermediate computed values.

band

a two components vector which give the definition `[ml,mu]` of band matrix computed by `jac` ;

`r(i - j + ml + mu + 1,j)` = `dg(i)/dy(j)+cj*dg(i)/dydot(j)` . If `jac` returns a full matrix set `band=[]`

maxstep

A scalar or an empty matrix, the maximum step size, empty matrix means "no limitation".

stepin

A scalar or an empty matrix, the minimum step size, empty matrix means "not specified".

nonneg

A scalar, must be set to 0 if ```the solution is known to be non negative.``` In the other case it must be set to 1.

isest

A scalar, must be set to 0 is the given initial condition is compatible: `g(t0,x0,xdot0)=0`. 1 an set to 1 if `xdot0` is just an estimation.