functionreadRealParameter

Read the value of a Real parameter from file

Extends from Modelica.Icons.Function (Icon for functions).

Information

Syntax

result = readRealParameter(fileName, name);

Description

This function demonstrates how a function can be implemented that reads the value of a parameter from file. The function performs the following actions:

  1. It opens file "fileName" and reads the lines of the file.
  2. In every line, Modelica line comments ("// ... end-of-line") are skipped
  3. If a line consists of "name = expression" and the "name" in this line is identical to the second argument "name" of the function call, the expression calculator Examples.expression is used to evaluate the expression after the "=" character. The expression can optionally be terminated with a ";".
  4. The result of the expression evaluation is returned as the value of the parameter "name".

Example

On file "test.txt" the following lines might be present:

// Motor data
J        = 2.3     // inertia
w_rel0   = 1.5*2;  // relative angular velocity
phi_rel0 = pi/3

The function returns the value "3.0" when called as:

readRealParameter("test.txt", "w_rel0")

Inputs

TypeNameDefaultDescription
StringfileNameName of file
StringnameName of parameter
BooleanuseDefaultValuefalseIf true, then the default value is returned if parameter not found in file, else an error is printed
RealdefaultValue0Return value if parameter not found in file

Outputs

TypeNameDefaultDescription
RealresultActual value of parameter on file