Hierarchical Modification

Hierarchical modification means that elements one or more levels down in the instantiation hierarchy are modified. Such modifiers can use nested notation, using parenthesis, or dot notation.

1 LowPassFilter

model LowPassFilter parameter Real T = 1; parameter Real k = 1; Real u, y(start = 1,fixed=true); equation T*der(y) + y = k*u; end LowPassFilter;

Two instances of the filter with different time constants T are put together to form the class FiltersInSeries.

model FiltersInSeries LowPassFilter F1(T=2), F2(T=3); // Two instances with different T's are created equation F1.u = sin(time); F2.u = F1.y; end FiltersInSeries;

Finally, two different instances F12 and F34 of FiltersInSeries are created in the class ModifiedFiltersInSeries with modified time constants. Both instances have identical time constants, but the first uses nested notation and the second uses dot notation for hierarchical modification.

model ModifiedFiltersInSeries FiltersInSeries F12(F1(T = 6), F2(T = 11, k = 2)); // Nested notation FiltersInSeries F34(F1.T = 6, F2.T = 11, F2.k = 2); // Dot notation end ModifiedFiltersInSeries;

2 Simulation of LowPassFilter

simulate( ModifiedFiltersInSeries, stopTime=10 )
plot( F12.F1.u )

plot( F12.F2.u )

plot( F34.F1.u )

plot( F34.F2.u )

3 More Usage of Nested and Dot Notation

Another example of hierarchical modification is shown for the class A, where the instance nested uses nested syntax and the instance dot uses dot notation.

class A Real x; end A;
class Hierarchical A nested(x (unit = "V", DisplayUnit = "mV") = 5.0); A dot (x.unit = "V", x.DisplayUnit = "mV", x = 5.0); end Hierarchical;