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c3dr (version 0.2.0)

c3d_read: Read a c3d file in R

Description

Import a c3d file using the C++ ezc3d library.

Usage

c3d_read(file)

Value

A list of class c3d.

Arguments

file

A string with the path of a c3d file.

Details

This function reads a c3d file with biomechanical data. It returns a c3d object, which is a list of all imported data.

The resulting c3d object has the following entries:

  • header: A list with header parameters containing general meta data for the recording. nframes is the total number of frames recorded. npoints is the total number of points recorded. nanalogs is the number of analog channels. analogperframe is the rate of analog frames per point recording frame. framerate is the number of point frames per second. nevents is the number of recorded events.

  • parameters: A list with meta data of the recording. The parameters are organized in groups, similarly to the original structure in the c3d file. c3dr tries to preserve the data type and data structure of each imported parameter value. One-dimensional parameters are imported as a scalar or vector, two-dimensional parameters are imported as a matrix, three-dimensional parameters are imported as a list of matrices.

  • data: A list with the point data of the recording. Each element in the list corresponds to one frame. Use c3d_data() to convert the data to a data frame.

  • analog: A list with the analog data of the recording. Each element of the list corresponds to one frame of the point recording and contains a matrix with all analog channels (as columns) for all subframes (as rows). Use c3d_analog() to convert the data to a data frame.

  • forceplatform: A list with force platform data, if available. Each element in the list corresponds to one force platform. Each force platform is another list with the following elements: forces is a matrix of the forces. moments is a matrix of the moments. tz is a matrix of the moments on the center of pressure. meta is a list with further meta data of the force platform recording (frames, funit unit of force, munit unit of moments, punit unit of center of pressure position, calmatrix calibration matrix, corners position of the corners, origin position of the origin).

Examples

Run this code
# get example data path
path <- c3d_example()

d <- c3d_read(path)
str(d)

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