mt_check_resolution computes the timestamp differences as a measure of
the logging resolution. It provides various descriptive statistics to check
the logging resolution.
mt_check_resolution( data, use = "trajectories", timestamps = "timestamps", desired = NULL, digits = NULL )
a mousetrap data object created using one of the mt_import
functions (see mt_example for details). Alternatively, a trajectory
array can be provided directly (in this case
use will be ignored).
a character string specifying which trajectory data should be used.
a character string specifying the trajectory dimension containing the timestamps.
an optional integer. If specified, additional statistics are computed concerning the (relative) frequencies with which exactly the desired timestamp difference (with tolerance 1e-12) occurred.
an optional integer. If specified, timestamps will be rounded before performing any checks. Potentially useful if timestamps are recorded with submillisecond precision.
A list with various descriptive statistics. For convenience, the relative frequencies are rounded to 4 decimal places.
If mouse-tracking experiments are conducted using the mousetrap plug-ins for
OpenSesame, the logging resolution can be specified explicitly in the
experiment under "Logging resolution", which corresponds to the delay (in
milliseconds) between recordings of the mouse position. By default, mouse
positions are recorded every 10 ms (corresponding to a 100 Hz sampling rate).
As the actual resolution achieved depends on the performance of the hardware,
it makes sense to check the logging resolution using
mt_check_resolution. Note that delays smaller than the specified delay
typically result from mouse clicks in the experiment.
mt_check_resolution(mt_example) #> $summary #> Min. 1st Qu. Median Mean 3rd Qu. Max. #> 1.000 10.000 10.000 9.977 10.000 14.000 #> #> $sd #>  0.4015953 #> #> $frequencies #> log_diffs #> 1 2 3 4 6 7 8 10 11 14 #> 4 7 4 1 8 4 8 7504 5 1 #> #> $relative_frequencies #> log_diffs #> 1 2 3 4 6 7 8 10 11 14 #> 0.0005 0.0009 0.0005 0.0001 0.0011 0.0005 0.0011 0.9944 0.0007 0.0001 #>