functionregStep
Approximation of a general step, such that the characteristic is continuous and differentiable
Extends from Modelica.Icons.Function (Icon for functions).
Information
This function is used to approximate the equation
y = if x > 0 then y1 else y2;
by a smooth characteristic, so that the expression is continuous and differentiable:
y = smooth(1, if x > x_small then y1 else
if x < -x_small then y2 else f(y1, y2));
In the region -x_small < x < x_small a 2nd order polynomial is used for a smooth transition from y1 to y2.
Inputs
| Type | Name | Default | Description |
|---|---|---|---|
| Real | x | Abscissa value | |
| Real | y1 | Ordinate value for x > 0 | |
| Real | y2 | Ordinate value for x < 0 | |
| Real | x_small | 1e-5 | Approximation of step for -x_small <= x <= x_small; x_small >= 0 required |
Outputs
| Type | Name | Default | Description |
|---|---|---|---|
| Real | y | Ordinate value to approximate y = if x > 0 then y1 else y2 |
Revisions
- April 29, 2008
by Martin Otter:
Designed and implemented. - August 12, 2008
by Michael Sielemann:
Minor modification to cover the limit casex_small -> 0without division by zero.