Description Usage Arguments Value Note Author(s) See Also Examples

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 *λ^{(t,s)}_1*, *λ^{(t,s)}_2*, *λ^{(t,s)}_3*, *λ^{(t,s)}_4*, *λ^{(t,s)}_5*, *τ^{(t,s)}*, *τ^{(t,s)}_3*, *τ^{(t,s)}_4*, and *τ^{(t,s)}_5*. The function supports TL-moments and TL-moment ratios of arbitrary length. Because in typical practice the *k ≥ 3* order L-moments are dimensionless ratios (*τ^{(t,s)}_3*, *τ^{(t,s)}_4*, and *τ^{(t,s)}_5*), this function computes *λ^{(t,s)}_3*, *λ^{(t,s)}_4*, *λ^{(t,s)}_5* from *λ^{(t,s)}_2* and the ratios. However, typical practice is not set on the use of *λ^{(t,s)}_2* or *τ^{(t,s)}* as measure of dispersion. Therefore, this function takes an `lscale`

optional logical argument—if *λ^{(t,s)}_2* is provided and `lscale=TRUE`

, then *τ* is computed by the function and if *τ* is provided, then *λ^{(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.

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`vec` |
A vector of L-moment values in |

`...` |
The arguments used by |

An **R** `list`

is returned where *t* represents the `trim`

level.

`lambdas` |
Vector of the TL-moments. First element is |

`ratios` |
Vector of the L-moment ratios. Second element is |

`trim` |
Level of symmetrical trimming, which should equal |

`leftrim` |
Level of trimming of the left-tail of the sample. |

`rightrim` |
Level of trimming of the right-tail of the sample. |

`source` |
An attribute identifying the computational source of the L-moments: “TLmoms”. |

The motiviation for this function that arrange trivial arguments for `vec2lmom`

is that it is uncertain how TL-moments will grow in the research community and there might someday be a needed for alternative support without having to touch `vec2lmom`

. Plus there is nice function name parallelism in having a dedicated function for the TL-moments as there is for L-moments and probability-weighted moments.

W.H. Asquith

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lmomco documentation built on Nov. 17, 2017, 7:25 a.m.

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