Changing the status of a variable

LA status changing

When you select Linear Analysis mode , the interface of the contextual window that lists the variables of a component changes. The columns for time domain analysis disappear and a column for the status of the variable in the frequency domain analysis appears.

Figure 17: Contextual window

If the variable is a state variable, the status setting options are dedicated to retrieve the dynamics of the phenomenon of your system.

Figure 18: Status of a state variable

For other variables, the status setting options are mainly dedicated to defining the perturbations that affect the dynamics of your system.

Figure 19: Status of a variable

Note

In this specific version interface of the contextual variable window, you can still plot a variable using the drag-and-drop on the sketch.

Changing the status globally

For the status of state variable, there is a quick way of changing it based on a multi-selection of components.

Select a part of the system you are interested in or select the whole system. From the Linear analysis menu, select All states observer or No states observer items:

• All states observer State observer all state observers The status of all the state variables of the selected components is switched to state observer.

• No states observer State observer no state observers The status of all the state variables of the selected components is switched to free state.

Results

Figure 20: State variables: global change of status

Changing the status of a vector variable

The status of a vector of state variable can be displayed in two ways depending on whether the option Expand vectors is enabled.

Figure 21: Expand vectors option

Linear Analysis status with vectors

If the option is checked then each component of the vector can be set individually.

Figure 22: Vector variable: single change of status

If the option is not checked, all components of the vector are assigned the same status.

Current status of all variables

To check the current status of variables, click on or use the LA Status menu option to open the LA Status Fields window.

Figure 23: LA Status Fields

The information is stored in 4 lists under the headings Free states, Fixed states, Control variables and Observer variables.

If a state variable is also an observer variable, it appears in both the Free states and the Observer variables lists. This is the only occasion when a variable can appear on more than one list.

Under each item is an output variable. If a corresponding input variable exists, this is also added prefixed by a ‘~’.

You cannot change anything in the dialog box. Any changes must be made as explained previously.