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Momocs (version 1.4.1)

sfourier: Radii variation Fourier transform (equally spaced curvilinear abscissa)

Description

sfourier computes radii variation Fourier analysis from a matrix or a list of coordinates where points are equally spaced aong the curvilinear abscissa.

Usage

sfourier(x, nb.h)
# S3 method for default
sfourier(x, nb.h)
# S3 method for Out
sfourier(x, nb.h)
# S3 method for list
sfourier(x, nb.h)

Value

A list with following components:

  • an vector of \(a_{1->n}\) harmonic coefficients

  • bn vector of \(b_{1->n}\) harmonic coefficients

  • ao ao harmonic coefficient

  • r vector of radii lengths

Arguments

x

A list or matrix of coordinates or an Out object

nb.h

integer. The number of harmonics to use. If missing, 12 is used on shapes; 99 percent of harmonic power on Out objects, both with messages.

References

Renaud S, Michaux JR (2003): Adaptive latitudinal trends in the mandible shape of Apodemus wood mice. J Biogeogr 30:1617-1628.

See Also

Other sfourier: sfourier_i(), sfourier_shape()

Examples

Run this code
molars[4] %>%
coo_center %>% coo_scale %>% coo_interpolate(1080) %>%
coo_slidedirection("right") %>%
   coo_sample(360) %T>% coo_plot(zoom=2) %>%
   sfourier(16) %>%
   sfourier_i() %>%
   coo_draw(bor="red", points=TRUE)

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