tagtools (version 0.2.0)

inclination: Estimate the inclination angle

Description

This function is used to estimate the local magnetic field vector inclination angle directly from acceleration and magnetic field measurements.

Usage

inclination(A, M, fc = NULL)

Value

The magnetic field inclination angle in radians.

Arguments

A

The accelerometer data structure or signal matrix, A = [ax,ay,az] in any consistent unit (e.g., in g or m/s2). A can be in any frame.

M

The magnetometer data structure or signal matrix, M = [mx,my,mz] in any consistent unit (e.g., in uT or Gauss). M must be in the same frame as A.

fc

(optional) The cut-off frequency of a low-pass filter to apply to A and M before computing the inclination angle. The filter cut-off frequency is with respect to 1=Nyquist frequency. Filtering adds no group delay. If fc is not specified, no filtering is performed.

Examples

A <- matrix(c(1, -0.5, 0.1, 0.8, -0.2, 0.6, 0.5, -0.9, -0.7),
  byrow = TRUE, nrow = 3, ncol = 3
)
M <- matrix(c(1.3, -0.25, 0.16, 0.78, -0.3, 0.5, 0.5, -0.49, -0.6),
  byrow = TRUE, nrow = 3, ncol = 3
)
incl <- inclination(A, M)