Functions with Multiple Results

A function that has more than one output parameter has multiple results.

function multipleResultsFunction input Real x; input Real y; output Real r1; output Real r2; output Real r3; algorithm r1 := x + y; r2 := x * y; r3 := x - y; end multipleResultsFunction;

Call it directly:

multipleResultsFunction(2.0, 1.0)
class MRFcall Real a, b, c; equation (a, b, c) = multipleResultsFunction(2.0, 1.0); end MRFcall;

1 Simulation of Call to MultipleResultsFunction

simulate( MRFcall, stopTime=10 )
plot( {a,b,c} )

2 PointOnCircle

Another example of a multiple results function is the function pointOnCircle, which computes the cartesian coordinates of a point located at a certain angle on a circle with a certain radius. The cartesian coordinates are returned via the two result variables x and y.

function pointOnCircle "Computes cartesian coordinates of a point" input Real angle "Angle in radians"; input Real radius; output Real x; // 1:st result formal parameter output Real y; // 2:nd result formal parameter algorithm x := radius*cos(angle); y := radius*sin(angle); end pointOnCircle;

Call it:

pointOnCircle(1.2, 2)

load Modelica library

loadModel(Modelica)
function pointOnCircle2 "Computes cartesian coordinates of a point" input Real angle "Angle in radians"; input Real radius; output Real x; // 1:st result formal parameter output Real y; // 2:nd result formal parameter algorithm x := radius*cos(angle); y := radius*Modelica.Math.sin(angle); end pointOnCircle2;

3 Function Call on Equation Form

When calling a multiple results functions there are two possibilities, equation form or statement form.

class PointOnCircleCall Real px, py; equation (px, py) = pointOnCircle(1.2, 2); end PointOnCircleCall;

4 Simulation of EquationCall

simulate( PointOnCircleCall )
plot( {px,py} )

5 Function Call on Statement Form

class StatementCall Real px, py; equation (px, py) = pointOnCircle(1.2, 2); end StatementCall;

6 Simulation of StatementCall

simulate( StatementCall )
{val(px,0), val(py,0)}