WOLFRAM SYSTEMMODELER

SMTH3

Third-order exponential smoothing

Diagram

Wolfram Language

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SystemModel["SystemDynamics.Functions.SMTH3"]
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Information

This is a third-order exponential smoothing function.

In engineering terms, this would be called a third-order low-pass filter consisting of three first-order low-pass filters placed in series. The third-order filter is characterized by the transfer function:

G(s) = (1/(tau*s + 1))^3.

Each first-order filter has a time constants of:

tau = averaging_time/3.

The initial values of the outputs of each of the three first-order filters can be set. However, they can only be set together, i.e., only one parameter is provided for all three of them. By default, they assume values of zero.

Public Parameters (2)

averaging_time

Value: 1

Type: Real

Description: Averaging time

smooth_init

Value: 0

Type: Real

Description: Initial value of smoothed variable

Connectors (2)

u

Type: RealInput

Description: Input variable

y

Type: RealOutput

Description: Output variable

Components (12)

Smooth1

Type: Level1a

Change_in_Smooth1

Type: Rate_1

source

Type: Source

ch_in_smooth1

Type: Change_In_Smooth

Smooth2

Type: Level1a

Change_in_Smooth2

Type: Rate_1

source1

Type: Source

ch_in_smooth2

Type: Change_In_Smooth

Smooth3

Type: Level1a

Change_in_Smooth3

Type: Rate_1

source2

Type: Source

ch_in_smooth3

Type: Change_In_Smooth

Used in Examples (1)

Human_Fertility

SystemDynamics.WorldDynamics.World3

Human fertility

Used in Components (3)

Pollution_Dynamics

SystemDynamics.WorldDynamics.World3

Pollution dynamics

NR_Resource_Utilization

SystemDynamics.WorldDynamics.World3

Utilization of non-recoverable natural resources

Food_Production

SystemDynamics.WorldDynamics.World3

Food production