Repetitive Equation Structures

1 Xpowers1

The polynomial equation where n = 4 can be expressed as a set of equations:

class Xpowers1 parameter Real x=10; Real a = 1; parameter Integer n = 5; Real xpowers[n]; Real y; equation xpowers[1] = 1; xpowers[2] = xpowers[1]*x; xpowers[3] = xpowers[2]*x; xpowers[4] = xpowers[3]*x; xpowers[4 + 1] = xpowers[4]*x; y = a * xpowers[5]; end Xpowers1;

2 Simulation of Xpowers1

Here the simulation of the XPowers1 is shown. The variables can then be plotted as below.

simulate( Xpowers1 )
plot( { xpowers[1], xpowers[2], xpowers[3], xpowers[4], xpowers[5] } )

3 Xpowers2

The same thing can be expressed more compactly as a simple equation together with a for-clause equation:

class Xpowers2 parameter Real x=10; Real xpowers[n]; parameter Integer i=1; parameter Integer n = 5; equation xpowers[1]=1; for i in 1:n-1 loop xpowers[i + 1] = xpowers[i]*x; end for; end Xpowers2;

4 Simulation of Xpowers2

Here the simulation of the XPowers2 is shown. The variables can then be plotted as below.

simulate( Xpowers2 )
plot( { xpowers[1], xpowers[2], xpowers[3], xpowers[4], xpowers[5] } )

5 Xpowers3

A very compact notation:

class Xpowers3 parameter Real x=10; Real xpowers[n+1]; parameter Integer n = 5; equation xpowers[1]=1; xpowers[2:n+1] = xpowers[1:n]*x; end Xpowers3;

6 Simulation of Xpowers3

Here the simulation of the XPowers3 is shown. The variables can then be plotted as below.

simulate( Xpowers3 )
plot( { xpowers[1], xpowers[2], xpowers[3], xpowers[4], xpowers[5] } )