diff_nh

Differentiate x and y and compute change amplitude via an algorithm proposed by Nyström 
and Holmqvist (2010) tools:::Rd_expr_doi("10.3758/BRM.42.1.188"). Note that both components and the amplitude are smoothed
independently via a Savitzky-Golay filter, so the components may not (probably won't) add up to
the amplitude. Note that filtering is sensitive to the presence of <code>NA</code>.

A modular and extendable approach to extract (micro)saccades from gaze samples via an ensemble of methods.
Although there is an agreement about a general definition of a saccade, the more specific details are harder to agree upon.
Therefore, there are numerous algorithms that extract saccades based on various heuristics, which differ in the assumptions about velocity,
acceleration, etc. The package uses three methods (Engbert and Kliegl (2003) <doi:10.1016/S0042-6989(03)00084-1>,
Otero-Millan et al. (2014)<doi:10.1167/14.2.18>, and Nyström and Holmqvist (2010) <doi:10.3758/BRM.42.1.188>)
to label individual samples and then applies a majority vote approach to identify saccades. The package includes three
methods but can be extended via custom functions. It also uses a modular approach to compute velocity and
acceleration from noisy samples. Finally, you can obtain methods votes per gaze sample instead of saccades.

Alexander (Sasha) Pastukhov

saccadr

Extract Saccades via an Ensemble of Methods Approach

Alexander Pastukhov

diff_nh function

<dl><dt>x</dt>
<dd>vector with x coordinates in degrees of visual angle</dd>
<dt>y</dt>
<dd>vector with y coordinates in degrees of visual angle</dd>
<dt>trial</dt>
<dd>vector with trial index</dd>
<dt>sample_rate</dt>
<dd>sample rate in Hz</dd>
<dt>options</dt>
<dd>List with method specific options, see Details.</dd></dl>

Arguments

Differentiate x and y and compute change amplitude via an algorithm proposed by Nyström and Holmqvist (2010) tools:::Rd_expr_doi("10.3758/BRM.42.1.188") — diff_nh

<dl>

<dt>x</dt>
<dd>vector with x coordinates in degrees of visual angle</dd>


<dt>y</dt>
<dd>vector with y coordinates in degrees of visual angle</dd>


<dt>trial</dt>
<dd>vector with trial index</dd>


<dt>sample_rate</dt>
<dd>sample rate in Hz</dd>


<dt>options</dt>
<dd>List with method specific options, see Details.</dd>

</dl>

Differentiate x and y and compute change amplitude via an algorithm proposed by Nyström and Holmqvist (2010) tools:::Rd_expr_doi("10.3758/BRM.42.1.188")

diff_nh: Differentiate x and y and compute change amplitude via an algorithm proposed by Nyström and Holmqvist (2010) tools:::Rd_expr_doi("10.3758/BRM.42.1.188")

Description

Usage

Value

Arguments

Details

See Also

Examples