Compound Stimulus¶

Description¶

A compound stimulus is a container for other stimuli. When displayed, it simply renders its child stimuli. For example, the following compound stimulus reproduces the flag of Ireland:

compound irish_flag {
    rectangle green_rect (
        color = 0.0075, 0.3278, 0.1221
        x_size = 4
        y_size = 6
        x_position = -4
        )

    rectangle white_rect (
        color = 1.0, 1.0, 1.0
        x_size = 4
        y_size = 6
        x_position = 0
        )

    rectangle orange_rect (
        color = 1.0, 0.2462, 0.0482
        x_size = 4
        y_size = 6
        x_position = +4
        )
}

Compound stimuli simplify management of groups of stimuli that should always be displayed together. Instead of loading, unloading, queuing, or dequeuing each member of a group individually, you can load, unload, queue, or dequeue just the compound stimulus that contains them. For example, you can display the above stimulus as follows:

queue_stimulus (irish_flag)
update_display ()

Signature¶

stimulus/compound

Optional Parameters¶

deferred¶

Options:: no

yes

explicit
Default:: no

Controls when the stimulus is loaded. If no, the stimulus is loaded at experiment load time. If yes, the stimulus is loaded the first time it is queued. If explicit, the stimulus must be loaded explictly with Load Stimulus.

display¶

Name of the display on which the stimulus will be presented. If omitted, the default display (if available) will be used.

schematic¶

Example:: {'color': [0.2, 0.5, 0.8], 'line_width': 3}

This parameter has no influence on how the stimulus is presented on the stimulus display. Instead, it affects how the schematic for the stimulus appears on MWClient’s eye window.

If present, the parameter’s value must be a dictionary containing one or more of the following keys:

'color': Color of the schematic. The value must be a list of three numbers between 0 and 1 (inclusive), respresenting the red, green, and blue components of the desired color.
'line_width': Width, in display points, of the lines used to draw the schematic. The value must be a non-negative number. A value of zero means the lines should be as thin as possible.
'hidden': Visibility of the schematic. The value must be a boolean, where false means the schematic should be visible, and true means it should be hidden.
'fixation_window': Parameters for the schematic of a fixation point’s fixation window. The value must be a dictionary containing one or more of the preceding keys. (Note: For fixation points, by default the eye window draws a schematic for the fixation window but not the visible stimulus. To show the visible stimulus, include key 'hidden' with a false value at the top level of the schematic dictionary.)

Placement¶

Allowed at top level:	Yes
Allowed parent:	Compound Stimulus, Folder, Frame List Stimulus, Layer Stimulus, List Replicator, Movie Stimulus, Range Replicator, Stimulus Group
Allowed children:	Stimulus