Skip to contents

Inter-joint coordination variability across cycles

Source: R/coordination.R
coordinationVariability.Rd

The trial-to-trial (cycle-to-cycle) variability of the coordination measure – the deviation phase for continuous relative phase (linear SD) or the coupling- angle circular SD for vector coding – computed at each point of the (time-normalised) cycle. Coordination variability is a motor-control marker: abnormally high or low values accompany injury and neurological disease.

Usage

coordinationVariability(
  angle1_cycles,
  angle2_cycles,
  method = c("crp", "vector_coding")
)

Arguments

angle1_cycles, angle2_cycles

Numeric matrices cycles x points (each row one time-normalised cycle) of the two joints' angles.

method

"crp" (deviation phase, linear SD) or "vector_coding" (coupling-angle circular SD).

Value

a coordination_variability list: method, variability (per-point), mean_variability and measure (the per-cycle coordination matrix).

References

Hamill (2000); Needham (2014).

See also

continuousRelativePhase(), vectorCoding()

Examples

m <- matrix(sin(seq(0, 2 * pi, length.out = 50)), nrow = 5, ncol = 50,
            byrow = TRUE)
coordinationVariability(m, m)$mean_variability      # identical cycles -> 0
#> [1] 0