Construct a plantar-pressure movie

Creates a compact representation of a pressure-sensor grid sampled over time. Pressure values are expected in kPa, and grid pitch is expressed in mm. Negative sensor values are clamped to zero.

Usage

pressureMovie(
  pressure,
  sampling_rate,
  dx = 1,
  dy = 1,
  side = NA_character_,
  units = "kPa",
  heel_first = TRUE
)

Arguments

pressure

Numeric three-dimensional array with dimensions grid row by grid column by frame, or a list of equal-dimension numeric matrices.

sampling_rate

Sampling frequency in Hz.

dx, dy

Sensor-cell pitch in the mediolateral and anteroposterior directions, respectively, in mm.

side

Optional foot side, "left", "right", or NA.

units

Pressure units recorded in the source data. Calculations assume kPa.

heel_first

Logical; whether grid row 1 is the posterior (heel) end.

Value

A pressure_movie object.

References

Pataky TC (2012). Spatial resolution in plantar pressure measurement revisited. Journal of Biomechanics, 45:2116-2124.

Examples

x <- array(0, dim = c(4, 3, 10))
x[2, 2, ] <- 100
pressureMovie(x, sampling_rate = 100, dx = 5, dy = 5)
#> <pressure_movie> 4 x 3 cells, 10 frames at 100 Hz (unspecified side)
#>   pitch: 5 x 5 mm  duration: 0.09 s  pressure: kPa