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Page Revision: 2011/07/15 19:09
Radar area is an element that monitors the relation between a continuous positional input in an experiment and a certain "watched" area on the screen. By default, the positional input in experiments is provided by a mouse. Other elements can replace the mouse input with an input from other positional devices, like eye trackers and joysticks. You can always combine several sources of the positional input in a single experiment. You also can define an appropriate shape, position and size of the watched area on the screen and change them at the runtime (for instance, in dynamical tracking paradigms, like the smooth pursuit tasks).
Element Description
The radar area works with any input source only while the parent event is active. The element can work in one of three working modes:
Instant modeIn this mode the element detects when positional input enters the "watched area". When it happens, the element instantly switches into the triggered state (the trigger time is recorder and custom user code executed, if it's defined).
Fixation modeIn this mode the element detects when positional input enters the "watched area" and stays there for certain time duration. The duration is defined by the [Fixation duration] property of the element. When it happens, the element also switches into the triggered state.
Trapper modeIn this mode the element detects detection when the positional input leaves the "watched area" (assuming that it has been inside before activation of the parent event). This mode is handy for continuous monitoring of the fixation breaks.
You can choose only between the rectangular or elliptical shape for the "watched area". It's sufficient for most of scenarios but, however, you can always create radar areas with complex shapes by combining several radar area elements in the same event. In this case you may need to check the states of multiple radar area elements manually, in your snippets.
- Notice 1: the radar area element can be triggered only once during activation of the parent event. If you need multiple triggering, redesign your experiment flow (e.g. use several events) or reactivate the parent event. Alternately, reading [Is Over] property of the element will provide a status of positional input even after the element is triggered.
- Notice 2: the radar area element can be affected by the solar visual transformations if they are applied to the parent event. In such cases, relations between positional input and watched areas can be incorrectly estimated. Always place radar area elements in events that have no such transformations.
- Notice 3: if you have several active radar area elements that watch the same screen area they can be triggered at the same time.
Properties of Element
| Name | Description | Attributes | Value Type |
|---|
| Settings |
| Working mode | Defines the working mode for the element- its reaction on the positional input. One of three modes can be selected:
Instant- the element is triggered at the moment when the current positional input goes inside of the "watched area"
Fixation- the element is triggered if the current positional input stays in the "watched" area for the duration defines by the Fixation Duration property. It duration is set to 0, this mode is equivalent to the Instant mode.
Trapper- the element is triggered if the current positional input leaves the "watched" area. Can be used for continuous monitoring of the fixation break. | D |
| Fixation duration | Defines the duration (in ms) of the fixation interval when the element works in the "fixation" mode. Otherwise, the value is not used. | D,R | UInt64 |
| Runtime info |
| Is Over | Indicates at the runtime if the positional input is currently inside of the "watched area". | R, Read-only | Boolean |
| Trigger time | Shows event's time (ms) when the element was triggered. Event's time is the time passed since activation of the parent event. This property is recommended for obtaining the accurate reaction time data. | R, Read-only | UInt64 [ ] |
| Was triggered | Indicates if the element has been triggered starting from current activation of the parent event | R, Read-only | Boolean |
| Visual appearance |
| Border Visible | Defines if the perimeter of the "watched area" is shown at the runtime (e.g. in training sessions). | D,R* | Boolean |
| Area shape | Defines the shape of the watched area- ellipse or rectangle. | D | Int32 |
| Position | Defines the position (Cartesian, radial) of the point on the screen to which "watched" area is aligned. | D,R,* | clPoint
(X.Y,R,Theta) |
| Size | Defines the size (pixels, visual degrees) of the "watched" area on the screen. | D,R,* | clSize
(Width,Height,
aWidth,aHeight) |
| Z order | Indicates the visual depth order of the "watched" area on the surface of the parent event (if it's visible). Depends on relative position of the element in the elements list of the parent event. | R, Read-only |
| lignment | Defines alignment of the "watched" area to its position. The default value is the central alignment. | D,R,* | stAlignment
Int32 |
| Effects |
| Color mask | The selected color will set the effect of "look through the colored glass" on the perimeter border the element (if it's visible). The non-transparent colors will provide most adequate effect. White color means no effect. | D,R,* | clColor |
+=== Properties inherited from clElement ===
Inherited properties of clElement
| Name | Description | Constraints | Value Type | Upon Change |
|---|
| Control |
| Is Enabled | If set to false the element is completely omitted when the experiment is run. | | Boolean |
|
| Title | Title of the element. | | String |
|
The list of Text element properties:
Resource Holder inherited properties
| CATEGORY ,Property name | Description | type | Value type |
| RESOURCE LIST |
| Resource index | The index of item in the resource list that is currently used by the element. Notice, that index starts from 1. | D,R,* | Int32 |
| Resource count | The number of items loaded in the resource list of the element | D,R,Read-only | Int32 |
|