| Type: | Package | 
| Title: | Derive Leaf Angle Distribution (LAD) from Measured Leaf Inclination Angles | 
| Version: | 0.1.0 | 
| Maintainer: | Francesco Chianucci <fchianucci@gmail.com> | 
| Description: | Calculate mean statistics and leaf angle distribution type from measured leaf inclination angles. LAD distribution is fitted using a two-parameters (mu, nu) Beta distribution and compared with six theoretical LAD distributions. Additional information is provided in Chianucci and Cesaretti (2022) <doi:10.1101/2022.10.28.513998>. | 
| License: | MIT + file LICENSE | 
| Encoding: | UTF-8 | 
| LazyData: | true | 
| RoxygenNote: | 7.2.2 | 
| Imports: | cowplot, dplyr, ggplot2, magrittr, purrr, rlang, stats, tidyr, tidyselect, utils | 
| Depends: | R (≥ 2.10) | 
| NeedsCompilation: | no | 
| Packaged: | 2023-06-10 16:58:48 UTC; francescochianucci | 
| Author: | Francesco Chianucci | 
| Repository: | CRAN | 
| Date/Publication: | 2023-06-11 11:30:04 UTC | 
LAD: Derive Leaf Angle Distribution (LAD) from Measured Leaf Inclination Angles
Description
Calculate mean statistics and leaf angle distribution type from measured leaf inclination angles. LAD distribution is fitted using a two-parameters (mu, nu) Beta distribution and compared with six theoretical LAD distributions. Additional information is provided in Chianucci and Cesaretti (2022) doi:10.1101/2022.10.28.513998.
Author(s)
Maintainer: Francesco Chianucci fchianucci@gmail.com (ORCID)
Authors:
- Lorenzo Cesaretti lorenzo.cesaretti@crea.gov.it 
Pipe operator
Description
See magrittr::%>% for details.
Usage
lhs %>% rhs
Arguments
| lhs | A value or the magrittr placeholder. | 
| rhs | A function call using the magrittr semantics. | 
Value
The result of calling rhs(lhs).
Chianucci dataset
Description
The dataset provide measured leaf inclination angles from 138 temperate and boreal woody species.
Usage
Chianucci
Format
Chianucci
A data frame with 23,882 rows and 9 columns:
- N
- row ID record 
- ICP_Code
- ICP species code, when available 
- Family, Genus, Species
- Family, Genus, Species taxonomy information 
- Author_citation
- Species author name 
- Canopy_sector
- The portion of the canopy where the leaves have been measured 
- Angle_degree
- Measured leaf inclination angles (degree) 
- Date
- Date of sampling (dd-mm-yy) 
...
Source
Calculate summary statistics from measured leaf inclination angles
Description
The function derives summary statistics from measured leaf inclination angles:.
- Mean (MTA), standard deviation (SD) and frequency (NR) observations. 
- The two (mu, nu) Beta parameters derived from the formula provided by Goel and Strebel (1984) doi:10.2134/agronj1984.00021962007600050021x. 
- The distribution type, comparing the distribution against the six theoretical LAD distributions provided by de Wit (1965). 
Arguments
| data | Dataframe. The dataframe containing leaf inclination angle measurements. | 
| angles | Numeric. The column containing leaf inclination angle measurements (in degrees). | 
| type | Character. If set to "summary", it gives summary distributions. If set to "extended", it calculates LAD probability density (pdf) and G-function (G) for view or inclination angles (theta). Default set to "summary". | 
| ... | The column(s) indicating the grouping variables to be considered for calculating summary statistics. | 
Value
A dataframe with the grouping variable(s), and:
- summary statistics (MTA, SD, N, mu, nu, distribution) in case of type="summary"; 
- LAD (pdf) and G-function (G) in case of type="extended". 
Examples
head(Chianucci)
calcLAD(Chianucci,Angle_degree,type='summary',Genus,Species)
calcLAD(Chianucci,Angle_degree,type='extended',Genus,Species)
Fit Leaf Angle Distribution (LAD) from two-parameters (mu, nu) Beta distribution
Description
The function derives both the Leaf Angle Distribution (LAD) and the G-function from two-parameters (mu, nu) Beta distribution.
- The LAD function is fitted through a Beta distribution as recommended by Goel and Strebel (1984). 
- The G-function is derived from LAD using the formula provided by Ross (1981) and reported as Equations 2-3 by Chianucci et al. (2018). 
- The fitted LAD is also compared with six theoretical LAD distributions provided by de Wit (1965). 
- The distribution type is then classified using a leaf inclination index Ross (1975) and reported as Equation 8 by Chianucci et al. (2018). 
Arguments
| mu | Numeric. The mu parameter of the Beta distribution. | 
| nu | Numeric. The nu parameter of the Beta distribution. | 
| plot | Logical. If set to TRUE, it plots the measured and theoretical LAD and G distributions. Default set to FALSE. | 
Value
A list of two elements:
- dataset: a dataframe with three columns indicating the measured LAD (pdf), the G-function (G), for view or inclination angle (theta). 
- distribution: a vector containing the matched distribution type. 
Examples
fitLAD(0.9,0.9) # uniform LAD distribution
fitLAD(2.8,1.18)# planophile LAD distribution
fitLAD(1.1,1.7, plot=TRUE)# spherical LAD distribution