Fits the three-parameter Gamma (Pearson type III)
distribution to an xts series by the method of L-moments. Parameters
are obtained via pelpe3 and then transformed to
the standard location, scale, and shape parameterisation used
throughout the package. 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.
Usage
fitlm_gamma3(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(rgamma3(365, location = 5, scale = 0.5, shape = 3),
order.by = as.Date("2020-01-01") + 0:364)
fit <- fitlm_gamma3(x)
fit$Param
#> $location
#> [1] 3.952122
#>
#> $scale
#> [1] 0.6040903
#>
#> $shape
#> [1] 4.269671
#>
