functionregRoot
Anti-symmetric square root approximation with finite derivative in the origin
Extends from Modelica.Icons.Function (Icon for functions).
Information
This function approximates sqrt(abs(x))*sgn(x), such that the derivative is finite and smooth in x=0.
| Function | Approximation | Range |
|---|---|---|
| y = regRoot(x) | y ~= sqrt(abs(x))*sgn(x) | abs(x) >>delta |
| y = regRoot(x) | y ~= x/sqrt(delta) | abs(x) << delta |
With the default value of delta=0.01, the difference between sqrt(x) and regRoot(x) is 16% around x=0.01, 0.25% around x=0.1 and 0.0025% around x=1.
Inputs
| Type | Name | Default | Description |
|---|---|---|---|
| Real | x | ||
| Real | delta | 0.01 | Range of significant deviation from sqrt(abs(x))*sgn(x) |
Outputs
| Type | Name | Default | Description |
|---|---|---|---|
| Real | y |
Revisions
- 15 Mar 2005
by Francesco Casella:
Created.