This function converts a vector of trimmed L-moments (TL-moments) to a TL-moment object of lmomco by dispatch to vec2lmom. The object is an R list. This function is intended to facilitate the use of TL-moments that the user might have from other sources. The trimming on the left-tail is denoted by \(t\) and the trimming on the right-tail is denoted as \(s\). The first five TL-moments are \(\lambda^{(t,s)}_1\), \(\lambda^{(t,s)}_2\), \(\lambda^{(t,s)}_3\), \(\lambda^{(t,s)}_4\), \(\lambda^{(t,s)}_5\), \(\tau^{(t,s)}\), \(\tau^{(t,s)}_3\), \(\tau^{(t,s)}_4\), and \(\tau^{(t,s)}_5\). The function supports TL-moments and TL-moment ratios of arbitrary length. Because in typical practice the \(k \ge 3\) order L-moments are dimensionless ratios (\(\tau^{(t,s)}_3\), \(\tau^{(t,s)}_4\), and \(\tau^{(t,s)}_5\)), this function computes \(\lambda^{(t,s)}_3\), \(\lambda^{(t,s)}_4\), \(\lambda^{(t,s)}_5\) from \(\lambda^{(t,s)}_2\) and the ratios. However, typical practice is not set on the use of \(\lambda^{(t,s)}_2\) or \(\tau^{(t,s)}\) as measure of dispersion. Therefore, this function takes an lscale optional logical argument---if \(\lambda^{(t,s)}_2\) is provided and lscale=TRUE, then \(\tau\) is computed by the function and if \(\tau\) is provided, then \(\lambda^{(t,s)}_2\) is computed by the function. The trim level of the TL-moment is required. Lastly, it might be common for \(t=s\) and hence symmetrical trimming is used.
vec2TLmom(vec, ...)An R
list is returned where \(t\) represents the trim level.
Vector of the TL-moments. First element is \(\lambda^{(t,s)}_1\), second element is \(\lambda^{(t,s)}_2\), and so on.
Vector of the L-moment ratios. Second element is \(\tau^{(t,s)}\), third element is \(\tau^{(t,s)}_3\) and so on.
Level of symmetrical trimming, which should equal NULL if asymmetrical trimming is used.
Level of trimming of the left-tail of the sample.
Level of trimming of the right-tail of the sample.
An attribute identifying the computational source of the L-moments: “TLmoms”.
A vector of L-moment values in \(\lambda^{(t,s)}_1\), \(\lambda^{(t,s)}_2\) or \(\tau^{(t,s)}\), \(\tau^{(t,s)}_3\), \(\tau^{(t,s)}_4\), and \(\tau^{(t,s)}_5\) order.
The arguments used by vec2lmom.
W.H. Asquith
TLmoms, vec2lmom
TL <- vec2TLmom(c(12,0.6,0.34,0.20,0.05),lscale=FALSE,trim=1)
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