Contributions:EyetrackerLoggerTobii3 - Revision history

Mellinger: /* EyetrackerData */

2017-08-30T14:58:04Z

EyetrackerData

← Older revision		Revision as of 14:58, 30 August 2017
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	int32_t x = ...		int32_t x = ...
	uint32_t mask = ~((1<<N)-1);		uint32_t mask = ~((1<<N)-1);
	if~~(int32_t~~(x) & mask)		if(x & mask)
	x \|= mask;		x \|= mask;

Mellinger: More examples for clarity

2017-08-29T17:35:41Z

More examples for clarity

← Older revision		Revision as of 17:35, 29 August 2017
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	*''raw maximum'' (typically 0, but may indicate an estimated raw data maximum if different from ''raw minimum'').		*''raw maximum'' (typically 0, but may indicate an estimated raw data maximum if different from ''raw minimum'').

	'''~~Example~~:'''		'''Examples:'''
	<tt>EyetrackerData</tt> may contain a row labeled <tt>EyetrackerRightEyeGazeX</tt> with a data type of "int18" and a physical unit of "-6.3 1e-5 m 0 0". At some sample offset, the value of the <tt>EyetrackerRightEyeGazeX</tt> state may be read as 2345.		<tt>EyetrackerData</tt> may contain a row labeled <tt>EyetrackerRightEyeGazeX</tt> with a data type of "int18" and a physical unit of "-6.3 1e-5 m 0 0". At some sample offset, the value of the <tt>EyetrackerRightEyeGazeX</tt> state may be read as 2345.
	To recover the right gaze point's distance from the screen's left edge in original units,		To recover the right gaze point's distance from the screen's left edge in original units,
	you may proceed as follows:		you may proceed as follows:
			*interpret 2345 as a signed 18 bit number -> 2345
	*subtract -6.3 -> 2345-(-6.3) = 2351.3		*subtract -6.3 -> 2345-(-6.3) = 2351.3
	*multiply with 1e-5 -> 0.023513		*multiply with 1e-5 -> 0.023513
	*concatenate with "m" -> 0.023513m = 23.513mm.		*concatenate with "m" -> 0.023513m = 23.513mm.

			At another sample offset, the value of the <tt>EyetrackerRightEyeGazeX</tt> state may be read as 262138:
			*interpret 262138 as a signed 18 bit number -> -6
			*subtract -6.3 -> -6-(-6.3) = 0.3
			*multiply with 1e-5 -> 0.000003
			*concatenate with "m" -> 0.000003m = 0.03mm.

			'''Extending the sign bit:'''
			In order to interpret a positive 32-bit integer value as a signed N bit integer with N<32, bits
			18 to 31 must be set to the same value (1 or 0) as the sign bit.
			In Matlab, this may be achieved as follows:
			x = ...
			idx = find(x >= 2^(N-1));
			x(idx) = 2^N - x(idx);

			In C or C++, one may write
			int32_t x = ...
			uint32_t mask = ~((1<<N)-1);
			if(int32_t(x) & mask)
			x \|= mask;

	==State Variables==		==State Variables==

Mellinger: /* Documentation Parameters */

2017-08-22T18:41:42Z

Documentation Parameters

← Older revision		Revision as of 18:41, 22 August 2017
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	with the original [[Contributions:EyetrackerLogger\|EyetrackerLogger]].		with the original [[Contributions:EyetrackerLogger\|EyetrackerLogger]].

	===~~Documentation~~ Parameters===		===Descriptive Parameters===
	These parameters are used by the eye tracker logger in order to store information about		These parameters are used by the eye tracker logger in order to store information about
	the eye tracker's configuration, and to help interpretation of logged data in data analysis.		the eye tracker's configuration, and to help interpretation of logged data in data analysis.

Mellinger: /* See also */

2017-08-22T18:38:00Z

Mellinger: /* Coordinate System */

2017-08-22T18:28:21Z

Coordinate System

← Older revision		Revision as of 18:28, 22 August 2017
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	==Coordinate System==		==Coordinate System==
	When properly calibrated, the eye tracker will know location, orientation, and extent of the		When properly calibrated, the eye tracker will know about location, orientation, and extent of the
	display surface, relative to itself.		display surface, relative to itself.
	Observing the subject through a camera, the eye tracker will be able to detect eye position and gaze direction, relative to its own position and orientation.		Observing the subject through a camera, the eye tracker will be able to detect eye position and gaze direction, relative to its own position and orientation.

Mellinger: /* Coordinate System */

2017-08-22T18:27:46Z

Coordinate System

@@ Line 50: / Line 50: @@
 eye position in the same screen-relative coordinate system, extended with a Z axis perpendicular
 to the screen, as illustrated below:
 ==Parameters==

Mellinger: /* Usage and Calibration */

2017-08-22T18:04:59Z

Usage and Calibration

@@ Line 38: / Line 38: @@
 Quit the calibration utility before starting BCI2000.
 When you start the source module, ensure that the <code>--LogEyetrackerTobii3=1</code> command line parameter is set.
 ==Parameters==

Mellinger: /* EyetrackerLeftEyeValidity, EyetrackerRightEyeValidity */

2017-08-22T17:40:10Z

EyetrackerLeftEyeValidity, EyetrackerRightEyeValidity

← Older revision		Revision as of 17:40, 22 August 2017
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	===EyetrackerLeftEyeValidity, EyetrackerRightEyeValidity===		===EyetrackerLeftEyeValidity, EyetrackerRightEyeValidity===
	A number ranging between 0 and 4, representing the eye tracker's confidence to have identified		A number ranging between 0 and 4, representing the eye tracker's confidence to have identified
	the eye in question. As suggested in the Tobii3 SDK's manual, EyetrackerLoggerTobii3 will ignore		the eye in question. As suggested in the Tobii3 SDK's manual, <tt>EyetrackerLoggerTobii3</tt> will ignore
	any eye data with an associated validity value greater or equal to 2, but will report		any eye data with an associated validity value greater or equal to 2, but will report
	time stamp and validity value for that data point nevertheless.		time stamp and validity value for that data point nevertheless.

Mellinger: /* EyetrackerLeftEyeValidity, EyetrackerRightEyeValidity */

2017-08-22T17:39:41Z

EyetrackerLeftEyeValidity, EyetrackerRightEyeValidity

← Older revision		Revision as of 17:39, 22 August 2017
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	A number ranging between 0 and 4, representing the eye tracker's confidence to have identified		A number ranging between 0 and 4, representing the eye tracker's confidence to have identified
	the eye in question. As suggested in the Tobii3 SDK's manual, EyetrackerLoggerTobii3 will ignore		the eye in question. As suggested in the Tobii3 SDK's manual, EyetrackerLoggerTobii3 will ignore
	any ~~_eye_data_~~ with an associated validity value greater or equal to 2, but will report		any eye data with an associated validity value greater or equal to 2, but will report
	time stamp and validity value for that data point nevertheless.		time stamp and validity value for that data point nevertheless.
	When eye data are being ignored, all respective state variables will keep their previous values.		When eye data are being ignored, all respective state variables will keep their previous values.

Mellinger: /* State Variables */

2017-08-22T17:38:48Z

State Variables

← Older revision		Revision as of 17:38, 22 August 2017
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	==State Variables==		==State Variables==
	Unless otherwise specified, all states are prefixed with <code>Eyetracker<Left/Right>Eye</code> which corresponds with each individual eye. The EyetrackerLogger extension does not support eye tracking with multiple subjects.

	===EyetrackerTime===		===EyetrackerTime===
	Time stamp of eye data as reported by the eye tracker, and converted into time units compatible		Time stamp of eye data as reported by the eye tracker, and converted into time units compatible

← Older revision		Revision as of 18:38, 22 August 2017
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	[[User Reference:Logging Input]], [[Contributions:Extensions]], [[Contributions:EyetrackerLogger]]		[[User Reference:Logging Input]], [[Contributions:Extensions]], [[Contributions:EyetrackerLogger]]

	[[Category:Contributions]][[Category:~~Extensions~~]]		[[Category:Contributions]][[Category:Extension]]