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Interpolate AEP from Stage

Source: R/interpolation_functions.R
stage2aep.Rd

Given a stage-frequency curve, interpolates AEP values at target stages. Interpolation is performed in standard normal (z-variate) space for better behavior across orders of magnitude in AEP.

Usage

stage2aep(aep, stage, interp_stage)

Arguments

aep

Numeric vector of annual exceedance probabilities from the known curve.

stage

Numeric vector of stage values corresponding to aep.

interp_stage

Numeric vector of target stage values to interpolate at.

Value

Numeric vector of interpolated AEP values (same length as interp_stage).

Details

Stage-frequency curves typically flatten at very rare AEPs once the reservoir reaches the reservoir model discharge capacity. This produces tied stage values. approx() handles these by averaging the corresponding AEPs, which may emit a "collapsing to unique 'x' values" warning. This is expected behavior.

See also

aep2stage for the inverse operation.

Examples

# Get AEP at stage 3862.0-ft and 3872-ft
stage2aep(jmd_rfa_expected$AEP, jmd_rfa_expected$Expected, c(3862.0, 3872))
#> Warning: collapsing to unique 'x' values
#> [1] 0.011166982 0.001746593