Space normalize trajectories.

Adjust trajectories so that all trajectories have an identical start and end point. If no end points are provided, trajectories are only adjusted so that they have the same start position. Please note that this function is deprecated and that mt_align_start_end should be used instead, which provides the same (and additional) functionality.

mt_space_normalize(
  data,
  use = "trajectories",
  save_as = "sn_trajectories",
  dimensions = c("xpos", "ypos"),
  start = c(0, 0),
  end = NULL,
  verbose = FALSE
)

Arguments

data	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).
use	a character string specifying which trajectory data should be used.
save_as	a character string specifying where the resulting trajectory data should be stored.
dimensions	a character vector specifying the dimensions in the trajectory array that should be space-normalized.
start	a numeric vector specifying the start values for each dimension, i.e., the values the first recorded position should have in every trial.
end	a numeric vector specifying the end values for each dimension, i.e., the values the last recorded position should have in every trial. If NULL, trajectories are only adjusted so that they have the same start position.
verbose	logical indicating whether function should report its progress.

Value

A mousetrap data object (see mt_example) with an additional array (by default called sn_trajectories) containing the space-normalized trajectories. All other trajectory dimensions not specified in dimensions (e.g., timestamps) will be kept as is in the resulting trajectory array. If a trajectory array was provided directly as data, only the space-normalized trajectories will be returned.

References

Dale, R., Kehoe, C., & Spivey, M. J. (2007). Graded motor responses in the time course of categorizing atypical exemplars. Memory & Cognition, 35(1), 15-28.

See also

mt_align_start for aligning the start position of trajectories.

mt_remap_symmetric for remapping trajectories.

Author

Pascal J. Kieslich

Felix Henninger

Examples

if (FALSE) {
mt_example <- mt_space_normalize(mt_example,
  save_as ="sn_trajectories",
  start=c(0,0), end=c(-1,1))
}