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Rejection Sampling of Stage Bounded by a Probabilistic Maximum Stage

Source: R/rejection_sampling.R
rejection_sampling_stage.Rd

Draws n_samples stage values from a stage-frequency curve, rejecting any draws that exceed a probabilistic maximum stage (PMF) sampled from a three-parameter lognormal distribution. Accepted samples are ranked and assigned Weibull plotting positions for use in frequency analysis.

Usage

rejection_sampling_stage(
  pmf_stage_LN,
  stage_freq_df = NULL,
  aep = NULL,
  stage = NULL,
  n_samples = 1e+07
)

Arguments

pmf_stage_LN

A named list returned by pmf_stage_lognormal containing the lognormal PMF parameters.

stage_freq_df

A data frame with AEP in column 1 and stage in column 2. Mutually exclusive with aep and stage.

aep

Numeric vector of annual exceedance probabilities. Must be supplied with stage. Mutually exclusive with stage_freq_df.

stage

Numeric vector of stages corresponding to aep. Must be supplied with aep. Mutually exclusive with stage_freq_df.

n_samples

Integer. Number of samples to draw. Defaults to 1e7.

Value

A data frame of thinned accepted samples with columns for z-score and stage, suitable for plotting a probabilistically bounded stage-frequency curve. Output is produced by thin_samples().

See also

pmf_stage_lognormal

Examples

if (FALSE) { # \dontrun{
pmf_ln <- pmf_stage_lognormal(pmf_shift = 239, pmf_mean = 241.9, pmf_sigma = 0.5)

result <- rejection_sampling_stage(
  pmf_stage_LN  = pmf_ln,
  stage_freq_df = my_stage_freq_df,
  n_samples     = 1e7
)
} # }