Adjust Beta Distribution Parameters for Sensitivity Analyses

Expands (sd_mult > 1) or reduces (sd_mult < 1) the standard deviation of the Beta distribution. The Beta distribution has a maximum variance of mean(x) * (1 - mean(x), where mean(x) = alpha / (alpha + beta). If the inputs produce a desired variance that is greater than the maximum possible variance, or provides alpha and/or beta parameters that are < 1 and thus push more probability weight towards extreme probability values, this function returns alpha = 1 and beta = 1 (the uniform distribution).

Usage

sens_beta(alpha, beta, sd_mult = 2)

Arguments

alpha

The first shape parameter of the Beta distribution.

beta

The second shape parameter of the Beta distribution.

sd_mult

A non-negative multiplier on the standard deviation of the distribution.

Value

A named list of the adjusted distribution's parameters.

See also

Other sens_dist: sens_exp(), sens_gamma(), sens_gamma_pois(), sens_gamma_pois_zi(), sens_lnorm(), sens_neg_binom(), sens_norm(), sens_pois(), sens_skewnorm(), sens_student()

Examples

sens_beta(10, 10, 2)
#> $alpha
#> [1] 2.125
#> 
#> $beta
#> [1] 2.125
#> 
sens_beta(10, 10, 0.8)
#> $alpha
#> [1] 15.90625
#> 
#> $beta
#> [1] 15.90625
#>