## Main.AlgebraicVariables History

September 25, 2008, at 12:31 PM by 158.35.225.230 -
Changed lines 3-8 from:

Algebraic states are variables that do not have the differential operator (\$) applied in any equation. These algebraic states are

### Consistent Initial Conditions

Forward stepping algorithms such as DASSL, DASPK, or CVODE generally require ordinary differential equations (ODEs) or index-1 differential algebraic equations (DAEs) and consistent initial conditions. This is not a restriction with simultaneous methods as used by APMonitor. Also, ODEs or DAEs of any index can be solved.

to:

Algebraic states are variables that do not have the differential operator (\$) applied in any equation. These algebraic states are declared in the variables section.

September 25, 2008, at 12:30 PM by 158.35.225.230 -

## Algebraic Variables

Algebraic states are variables that do not have the differential operator (\$) applied in any equation. These algebraic states are

### Consistent Initial Conditions

Forward stepping algorithms such as DASSL, DASPK, or CVODE generally require ordinary differential equations (ODEs) or index-1 differential algebraic equations (DAEs) and consistent initial conditions. This is not a restriction with simultaneous methods as used by APMonitor. Also, ODEs or DAEs of any index can be solved.

### Example

(:table border=1 width=50% align=left bgcolor=#EEEEEE cellspacing=0:) (:cellnr:)

``` ! Example model with 2 algebraic equations
Model example
Parameters
p = 1
End Parameters

Variables
v1 = 1
v2 = 2
End Variables

Equations
v1 = v2 + p
2*v1 * v2 = v1^2
End Equations
End Model
```

(:tableend:)