Fits the three-parameter Generalised Logistic distribution
to an xts series by the method of L-moments. Parameters are obtained
in closed form via pelglo, which matches the
sample L-moment ratios to the theoretical L-moment ratios of the
Generalised Logistic distribution. Zero values below
zero_threshold may be excluded via ignore_zeros.
Goodness-of-fit is assessed via GOF_tests, and theoretical
L-moments are computed from the fitted parameters for comparison with
the sample.
Usage
fitlm_genlogi(x, ignore_zeros = FALSE, zero_threshold = 0.01)
Arguments
- x
An xts object containing the time series data.
- ignore_zeros
Logical. If TRUE, values below
zero_threshold are excluded. Default FALSE.
- zero_threshold
Numeric. Threshold below which values are treated
as zero. Default 0.01.
Value
A list with elements Distribution, Param (named
list of fitted parameters), TheorLMom (theoretical L-moments),
DataLMom (sample L-moments), and GoF (goodness-of-fit
metrics).
Examples
x <- xts::xts(qgenlogi(runif(365), location = 0, scale = 1, shape = -0.5),
order.by = as.Date("2020-01-01") + 0:364)
fit <- fitlm_genlogi(x)
fit$Param
#> $location
#> [1] -0.1545965
#>
#> $scale
#> [1] 0.9268245
#>
#> $shape
#> [1] -0.512855
#>
