tfourier computes tangent angle Fourier analysis from a matrix or a
list of coordinates.
tfourier(x, ...)
"tfourier"(x, nb.h, smooth.it = 0, norm = FALSE, verbose = TRUE, ...)
"tfourier"(x, nb.h = 40, smooth.it = 0, norm = TRUE, verbose = TRUE, ...)Outinteger. The number of harmonics to use. If missing 99pc harmonic power is used.integer. The number of smoothing iterations to
performlogical. Whether to scale and register new coordinates so
that the first point used is sent on the origin.logical. Whether to display diagnosis messages.ao ao harmonic coefficient
an vector of $a_{1->n}$ harmonic coefficients
bn vector of $b_{1->n}$ harmonic coefficients
phi vector of variation of the tangent angle
t vector of distance along the perimeter expressed in radians
perimeter numeric. The perimeter of the outline
thetao numeric. The first tangent angle
x1 The x-coordinate of the first point
y1 The y-coordinate of the first point.
Claude, J. (2008) Morphometrics with R, Use R! series, Springer 316 pp.
tfourier_i,
tfourier_shape
data(bot)
coo <- bot[1]
coo_plot(coo)
tf <- tfourier(coo, 12)
tf
tfi <- tfourier_i(tf)
coo_draw(tfi, border='red', col=NA) # the outline is not closed...
coo_draw(tfourier_i(tf, force2close=TRUE), border='blue', col=NA) # we force it to close.
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