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Build an orientation distribution for stored TMM post-processing

Source: R/tmm-orientation.R
tmm_orientation_distribution.Rd

Creates a validated set of incident angles and normalized weights that can be reused by tmm_average_orientation or tmm_products. The distributions defined here are distributions in theta_body itself rather than isotropic solid-angle distributions.

Usage

tmm_orientation_distribution(
  distribution = c("uniform", "normal", "truncated_normal", "quadrature", "pdf"),
  theta_body = NULL,
  weights = NULL,
  pdf = NULL,
  phi_body = pi,
  mean_theta = pi/2,
  sd_theta = pi/12,
  lower = 0,
  upper = pi,
  n_theta = 91
)

Arguments

distribution

Orientation-distribution type. One of "uniform", "normal", "truncated_normal", "quadrature", or "pdf".

theta_body

Optional numeric vector of incident polar angles (radians). Required for the "quadrature" and "pdf" pathways.

weights

Optional numeric quadrature weights paired with theta_body for distribution = "quadrature".

pdf

Optional user-supplied density over theta_body for distribution = "pdf". This can be either a numeric vector the same length as theta_body or a function evaluated at theta_body.

phi_body

Incident azimuth angle(s) (radians). Either scalar or the same length as the resolved theta_body grid.

mean_theta

Mean angle (radians) for the normal-family distributions.

sd_theta

Standard deviation (radians) for the normal-family distributions.

lower

Lower bound (radians) for the uniform and truncated-normal distributions.

upper

Upper bound (radians) for the uniform and truncated-normal distributions.

n_theta

Number of grid points for the analytic distributions.

Value

A data frame with normalized orientation weights and class "TMMOrientationDistribution".

See also

tmm_average_orientation, tmm_products

Examples

tmm_orientation_distribution(
  distribution = "uniform",
  lower = pi / 3,
  upper = 2 * pi / 3,
  n_theta = 7
)
#>   theta_body phi_body    weights distribution
#> 1   1.047198 3.141593 0.08333333      uniform
#> 2   1.221730 3.141593 0.16666667      uniform
#> 3   1.396263 3.141593 0.16666667      uniform
#> 4   1.570796 3.141593 0.16666667      uniform
#> 5   1.745329 3.141593 0.16666667      uniform
#> 6   1.919862 3.141593 0.16666667      uniform
#> 7   2.094395 3.141593 0.08333333      uniform