Package 'SamsaRaLight'

Check coordinate columns and determine whether conversion is required

Description

This function checks whether a data frame contains valid planar coordinates (x, y) or geographic coordinates (lon, lat). If geographic coordinates are detected, the user is informed that they must be converted to a planar coordinate system using create_xy_from_lonlat().

Usage

check_coordinates(df, verbose = TRUE)

Arguments

df	A data.frame containing spatial coordinates.
verbose	Logical. If TRUE, informative messages are printed.

Value

Logical. Invisibly returns TRUE if coordinates must be converted from longitude/latitude to planar coordinates, and FALSE if planar coordinates are already present.

Examples

df_xy <- data.frame(x = 1:3, y = 4:6)
check_coordinates(df_xy)

df_lonlat <- data.frame(lon = c(10, 11), lat = c(45, 46))
check_coordinates(df_lonlat, verbose = TRUE)

---

Check the format and validity of a tree inventory data.frame

Description

This function checks whether a tree inventory data.frame is correctly formatted to be used as input for the ray-tracing model. It verifies the presence, type, and validity of mandatory and optional variables describing the geometry and attributes of trees within a forest stand.

Usage

check_inventory(trees_inv, verbose = TRUE)

Arguments

trees_inv

A data.frame with one row per tree and the following columns: id_tree Unique identifier of the tree (numeric or character, no duplicates). x X position of the tree within the stand (numeric, meters, planar coordinates). Optional if lon and lat are provided. y Y position of the tree within the stand (numeric, meters, planar coordinates). Optional if lon and lat are provided. lon Longitude of the tree location (numeric, decimal degrees). Optional; if provided with lat, coordinates are converted internally to a UTM planar coordinate system in create_sl_stand(). lat Latitude of the tree location (numeric, decimal degrees). Optional; see lon. species Species name (character). dbh_cm Diameter at breast height (1.3 m, in cm). crown_type Type of crown geometry. One of "E", "P", "2E", "8E", or "4P". h_m Total tree height (numeric, meters). hbase_m Height of the crown base (numeric, meters). hmax_m Height of the maximum crown radius (numeric, meters). Required only if at least one tree has a crown type "2E" or "8E". For other crown types, the column is optional and the value is internally computed. rn_m Crown radius toward North (numeric, meters). rs_m Crown radius toward South (numeric, meters). re_m Crown radius toward East (numeric, meters). rw_m Crown radius toward West (numeric, meters). crown_lad Leaf Area Density (m2/m3). crown_openness Crown openness (unitless), optional if turbid medium interception. Required if the argument turbid_medium = FALSE in the advanced function run_sl_advanced() (for porous envelope interception). Otherwise, the basic function run_sl() will automatically computed interception in a turbid medium using the crown_lad variable.

verbose

Logical; if TRUE, informative messages and warnings are printed.

Details

The function performs the following checks and validations:

1

Ensures trees_inv is a non-empty data.frame with all required columns.

2

Checks that id_tree values are unique.

3

Checks that either planar coordinates (x, y) or geographic coordinates (lon, lat) are provided. If only lon and lat are supplied, they are converted to planar UTM coordinates in create_sl_stand(). The plot_inventory() function requires planar coordinates and cannot be used before this conversion.

4

Validates numeric columns (dbh_cm, h_m, hbase_m, rn_m, rs_m, re_m, rw_m) are numeric and non-negative.

5

Verifies that crown_type values are one of "E", "P", "2E", "8E", or "4P".

6

Ensures crown radii are present according to crown type.

7

Checks that hmax_m is provided when required and lies between hbase_m and h_m.

8

Ensures hbase_m < h_m.

9

Verifies that each tree has the crown LAD defined.

10

Provides informative error messages and warnings for all invalid conditions.

Value

Invisibly returns TRUE if all checks pass.

Examples

# Using the example dataset from the package
data_prenovel <- SamsaRaLight::data_prenovel
trees <- data_prenovel$trees

# Check the inventory
check_inventory(trees)

# Quiet mode
check_inventory(trees, verbose = FALSE)

---

Validate monthly radiation input

Description

Checks that a monthly radiation data.frame is correctly formatted and physically valid for use by the light interception and ray-tracing model. The table must contain exactly 12 months of radiation data.

Usage

check_monthly_radiations(x, verbose = TRUE)

Arguments

x	A data.frame with monthly radiation values, typically produced by get_monthly_radiations.
verbose	Logical; if TRUE, informative messages are printed.

Details

The input must contain the following columns:

month

Integer month number (1-12)

Hrad

Monthly global horizontal irradiation (MJ/m2)

DGratio

Diffuse-to-global radiation ratio (unitless, 0-1)

The function checks:

1

The object is a data.frame.

2

Required columns are present.

3

There are exactly 12 months.

4

Each month (1-12) is present exactly once.

5

Data are numeric and finite.

6

Hrad strictly positive.

7

DGratio between 0 and 1.

8

Months are in increasing order.

Value

Invisibly returns TRUE if all checks pass.

Examples

# Using the example dataset from the package
data_prenovel <- SamsaRaLight::data_prenovel
radiations <- data_prenovel$radiations

# Check the inventory
check_monthly_radiations(radiations)

# Quiet mode
check_monthly_radiations(radiations, verbose = FALSE)

---

Check and validate a polygon defined by vertices

Description

This function converts a data.frame of polygon vertices into an sf POLYGON and checks its validity. If the polygon is invalid, it attempts to fix it.

Usage

check_polygon(core_polygon_df, trees_inv, sensors = NULL, verbose = TRUE)

Arguments

core_polygon_df	A data.frame with columns x and y defining polygon vertices
trees_inv	A data.frame with one row per tree. See check_inventory for the required structure and validated columns.
sensors	Optional data.frame defining position and height of the sensor within the stand. See check_sensors for the required structure and validated columns.
verbose	Logical. If TRUE, warnings are printed

Value

A data.frame of polygon vertices (x, y):

• unchanged if valid

• modified if fixed (with a warning)

Examples

data_prenovel <- SamsaRaLight::data_prenovel

# Validate polygon
check_polygon(data_prenovel$core_polygon, data_prenovel$trees)

---

Check the format and validity of a sensor position data.frame

Description

This function checks whether a sensor data.frame is correctly formatted to be used as input for the ray-tracing model. It verifies the presence, type, and validity of mandatory variables describing the position and height of sensors within a forest stand.

Usage

check_sensors(sensors, verbose = TRUE)

Arguments

sensors	A data.frame with one row per sensor and the following columns: id_sensor Unique identifier of the sensor (numeric or character, no duplicates) x X position of the sensor (numeric, meters) y Y position of the sensor (numeric, meters) h_m Height above ground of the sensor (numeric, meters)
verbose	Logical; if TRUE, informative messages are printed.

Value

Invisibly returns TRUE if all checks pass.

Examples

sensors <- data.frame(
  id_sensor = 1:3,
  x = c(10, 20, 30),
  y = c(5, 15, 25),
  h_m = c(1.5, 2.0, 1.8)
)
check_sensors(sensors)

---

Create a virtual stand from a tree inventory

Description

This function builds a virtual forest stand from a user-provided tree inventory. The inventory zone (core polygon) can optionally be modified (e.g., replaced by an enclosing rectangle or an axis-aligned rectangle) before constructing the stand. Trees are spatially shifted so that the resulting inventory zone is centered within a regular grid of square cells. Optionally, additional trees can be added around the core inventory area to match its basal area per hectare.

Usage

create_sl_stand(
  trees_inv,
  cell_size,
  latitude,
  slope,
  aspect,
  north2x,
  sensors = NULL,
  core_polygon_df = NULL,
  modify_polygon = c("none", "rect", "aarect"),
  fill_around = FALSE,
  verbose = TRUE
)

Arguments

trees_inv	A data.frame with one row per tree. See check_inventory for the required structure and validated columns.
cell_size	Numeric. Side length of square cells composing the stand (meters).
latitude	Numeric. Latitude of the stand (degrees).
slope	Numeric. Slope of the plot (degrees).
aspect	Numeric. Aspect of the slope, defined as the azimuth of the downslope direction, clockwise from North (degrees). (0 degrees: North-facing slope, 90 degrees: East-facing slope, 180 degrees: South-facing slope, 270 degrees: West-facing slope)
north2x	Numeric. Clockwise angle from North to the X-axis (degrees). The default 90 degrees corresponds to a Y-axis oriented toward true North (0 degrees: x-axis points North, 90 degrees: x-axis points East, 180 degrees: x-axis points South, 270 degrees: x-axis points West).
sensors	Optional data.frame defining position and height of the sensor within the stand. See check_sensors for the required structure and validated columns.
core_polygon_df	Optional data.frame defining the core inventory polygon. Must contain columns x and y. If NULL, a concave hull is automatically computed from tree positions.
modify_polygon	Character. Defines how the inventory polygon is modified. One of: "none": the core polygon is used as provided or computed. "rect": the polygon is replaced by its minimum enclosing rectangle. "aarect": the polygon is replaced by an axis-aligned enclosing rectangle.
fill_around	Logical. If TRUE, trees are added outside the core polygon until the basal area per hectare of the full stand matches that of the core inventory.
verbose	Logical. If TRUE (default), messages and warnings are printed during processing. If FALSE, output is silent.

Details

The function supports sloping terrain and coordinate system rotation, and returns a fully prepared stand ready for use in the ray-tracing pipeline (see run_sl).

The returned trees data.frame conforms to the inventory format checked by check_inventory, with the following controlled modifications:

• Tree vertical position z is computed from terrain slope and aspect.

• Crown maximum radius height hmax_m is computed when fixed by crown geometry conventions:

  • "P" and "4P": hmax_m = hbase_m

  • "E" and "4E": hmax_m = hbase_m + 0.5 * (h_m - hbase_m)

  For crown types "2E" and "8E", hmax_m must be provided by the user.

• If missing, column dbh_cm is added and filled with NA.

• If missing, crown interception properties (e.g. crown_openness, crown_lad) are added using default values.

All input data.frames (trees_inv, sensors, and core_polygon_df) are automatically checked for coordinate type:

• If x and y columns exist, they are assumed to be planar.

• If lon and lat columns exist, they are converted into planar UTM coordinates automatically using create_xy_from_lonlat().

• The UTM projection (EPSG) is determined from the mean coordinates of trees_inv. All inputs must share the same EPSG; otherwise, the function stops with an error. If conversion occurred, the EPSG is stored in the output.

The function ensures that all trees fall within the core inventory polygon, applying small buffers if necessary to handle numerical precision issues. Invalid polygons are automatically repaired when possible.

When fill_around = TRUE, trees are randomly sampled from the original inventory and positioned outside the core polygon until the target basal area per hectare is reached for the full stand.

Value

A named list with the following elements:

trees

Data.frame of the final tree inventory, including added trees if fill_around = TRUE. The structure matches the inventory format validated by check_inventory, with additional derived variables required for ray tracing. A logical column added_to_fill indicates whether each tree originates from the initial inventory or was added to fill around the inventory zone.

core_polygon

List describing the inventory zone:

• df: data.frame of polygon vertices

• sf: corresponding sf POLYGON

• modify_polygon: applied polygon modification

transform

List of transformation and filling information, including core area, target and final basal area, number of added trees, and applied spatial transformations.

geometry

List describing stand geometry and terrain parameters (cell size, number of cells, slope, aspect, and orientation).

Examples

data_prenovel <- SamsaRaLight::data_prenovel
trees_inv <- data_prenovel$trees

stand <- create_sl_stand(
  trees_inv = trees_inv,
  cell_size = 10,
  latitude = 46.52666,
  slope = 6,
  aspect = 144,
  north2x = 54
)

---

Create planar (x, y) coordinates from longitude / latitude

Description

This function converts geographic coordinates (lon, lat) into planar coordinates (x, y) using an automatically selected UTM projection.

Usage

create_xy_from_lonlat(df)

Arguments

df	A data.frame containing geographic coordinates (lon and lat).

Details

The input data.frame must contain geographic coordinates (lon and lat). Planar coordinates (x, y) are automatically computed using the UTM zone inferred from the mean longitude and hemisphere inferred from the mean latitude.

Value

A list with the following elements:

df

The input data.frame with added x and y columns (meters, UTM).

epsg

EPSG code of the UTM projection used.

Examples

# Example data with longitude / latitude (WGS84)
df <- data.frame(
  lon = c(4.35, 4.36),
  lat = c(50.85, 50.86)
)

# Convert to planar coordinates (UTM)
res <- create_xy_from_lonlat(df)

# Access results
res$df   # data.frame with x, y columns
res$epsg # EPSG code used

---

Compute bottom azimut

Description

Compute bottom azimut

Usage

get_bottom_azimut(aspect, north2x)

Arguments

aspect	double - Angle of slope bottom on the compass from the North, clockwise rotation (in degrees) northern aspect : 0, eastern aspect : 90, southern aspect : 180, western aspect : 270
north2x	double - Angle from North to x axis clockwise. (in degrees) Default correspond to a Y axis oriented toward the North.

Value

a bottom azimuth numeric value

---

Create the SamsaraLight

Description

Fetch monthly radiation data from PVGIS website (by API) between start and end year (limit years are from 2005 to 2020). Fetched variables are Hrad = horizontal plane irradiation and DGratio = ratio of diffuse to global radiation (in horizontal plane).

! YOU NEED AN INTERNET CONNECTION TO ACCESS THE DATA BY API !

Usage

get_monthly_radiations(latitude, longitude, start_year = 2005, end_year = 2020)

Arguments

latitude	latitude of the plot
longitude	longitude of the plot
start_year	positive integer between 2005 and 2020 - start year on which to fetch monthly data
end_year	positive integer between 2005 and 2020 - end year on which to fetch monthly data

Value

Monthly horizontal radiation (Hrad) and diffuse to global ratio (DGratio) averaged between start_year and end_year

Source

https://joint-research-centre.ec.europa.eu/pvgis-photovoltaic-geographical-information-system_en

Examples

# Example: fetch monthly radiation somewhere in Belgium
rad <- get_monthly_radiations(
  latitude = 50.85,
  longitude = 4.35,
  start_year = 2010,
  end_year = 2015
)

head(rad)

---

Compute z coordinate of a point (x,y).

Description

Compute z coordinate of a point (x,y).

Usage

get_z(x, y, slope_rad, bottom_azimut_rad)

Arguments

x	X-coordinate of the point
y	Y-coordinate of the point
slope_rad	Slope of the stand (in radians)
bottom_azimut_rad	Azimuth of the vector orthogonal to the ground in the x,y system (in radians)

Value

a z coordinate numeric value

---

Plot a from-above view of a tree inventory

Description

Visualizes a forest inventory as ellipses representing tree crowns.

Usage

plot_inventory(trees_inv, core_polygon_df = NULL, show_id = TRUE)

Arguments

trees_inv	A data.frame of trees that passed check_inventory.
core_polygon_df	Optional data.frame defining the core inventory polygon. Must contain columns x and y.
show_id	Logical; if TRUE (default), displays tree identifiers at crown centers.

Details

Because the north2x variable is unknown, trees are plotted as circles by considering the mean radius on the four cardinals.

Value

A ggplot object displaying the trees in a from-above view.

Examples

data_prenovel <- SamsaRaLight::data_prenovel
trees_inv <- data_prenovel$trees

plot_inventory(trees_inv)

---

Plot a SamsaRaLight output

Description

Visualize ground light and tree energy metrics for a sl_output object.

Usage

## S3 method for class 'sl_output'
plot(
  x,
  ...,
  what_trees = c("compet", "intercepted", "potential"),
  what_cells = c("relative", "absolute"),
  show_trees = TRUE,
  direct_energy = NULL
)

Arguments

x	An object of class sl_output, returned by run_sl().
...	Additional arguments passed to lower-level plotting functions.
what_trees	Character; which tree metric to plot. Choices are: "compet" Light competition index (LCI), reversed viridis scale. "intercepted" Intercepted energy (MJ). "potential" Potential intercepted energy (MJ). Default is "compet".
what_cells	Character; which cell (ground) metric to plot. Choices are: "relative" Proportion of above canopy light (PACL)). "absolute" Energy on the ground (MJ/m2). Default is "relative".
show_trees	Logical; whether to display trees on top of the ground light map. Default is TRUE.
direct_energy	Logical or NULL. If NULL (default), total radiation outputs are plotted (direct + diffuse). If TRUE, only direct radiation components are plotted. If FALSE, only diffuse radiation components are plotted. This option requires detailed_output = TRUE when running the simulation

Value

A ggplot object.

---

Plot a SamsaRaLight virtual stand

Description

This function plots a virtual forest stand (sl_stand) produced by SamsaRaLight. It can display a top-down view with tree crowns or a side/top view with cells and trees.

Usage

## S3 method for class 'sl_stand'
plot(x, ..., top_down = FALSE, only_inv = FALSE, add_sensors = TRUE)

Arguments

x	An object of class sl_stand.
...	Additional arguments passed to lower-level plotting functions.
top_down	Logical, if TRUE, creates a top-down view with multiple directions (south, north, west, east).
only_inv	Logical, if TRUE, plot only trees from the initial inventory (i.e. not trees added to fill around the core polygon)
add_sensors	Logical; if TRUE (default), sensors are drawn on the plot. In top-down mode, sensors are shown as segment from ground to their height; in map view, sensors are drawn as squares on the ground.

Details

For the sake of the representation in top-down plot, z are offset such as minimum altitude tree is at Y-axis height = 0

The plot function also generates a compass indicating:

• Plot orientation (north2x, north in red)

• Terrain aspect (downslope direction)

• Slope degrees (annotation only)

Value

A ggplot object representing the stand.

---

Print a sl_output object

Description

Prints a concise one-line summary of a SamsaRaLight simulation result, reporting the number of cells, trees, and sensors, and whether detailed outputs are available.

Usage

## S3 method for class 'sl_output'
print(x, ...)

Arguments

x	An object of class sl_output.
...	Further arguments passed to or from other methods (ignored).

Value

The object x, invisibly.

---

Print a sl_stand object

Description

Prints a compact, human-readable, one-line description of a sl_stand object, summarizing the stand size, number of trees, number of sensors, and grid geometry.

Usage

## S3 method for class 'sl_stand'
print(x, ...)

Arguments

x	An object of class sl_stand.
...	Unused. Included for S3 method compatibility.

Details

This method is automatically called when a sl_stand object is printed in the console.

Value

The input object x, invisibly.

---

Run SamsaRaLight radiative balance

Description

This function computes light interception and radiative balance for a forest stand using the SamsaRaLight ray-tracing engine.

Usage

run_sl(
  sl_stand,
  monthly_radiations,
  sensors_only = FALSE,
  detailed_output = FALSE,
  parallel_mode = FALSE,
  n_threads = NULL,
  verbose = TRUE
)

Arguments

sl_stand	An object of class "sl_stand" describing the forest stand, created with create_sl_stand. It contains trees, sensors, terrain, and grid geometry.
monthly_radiations	A data.frame of monthly horizontal radiation (Hrad, in MJ m$^{-2}$) and diffuse-to-global ratio (DGratio), typically obtained using get_monthly_radiations and checked using check_monthly_radiations..
sensors_only	Logical. If TRUE, compute light interception only for sensors (much faster).
detailed_output	Logical. If TRUE, the output contains detailed diffuse/direct energies in the light datasets, full interception matrices interceptions and output of ray discretization monthy_rays. If FALSE, only total energies are returned (recommended for most uses).
parallel_mode	logical. If TRUE, ray–target computations are parallelised using OpenMP. If FALSE, the model runs in single-thread mode. SamsaRaLight uses OpenMP for ray–target parallelisation. To avoid competition between OpenMP and BLAS (matrix algebra libraries), BLAS is automatically forced to single-thread mode during the simulation. Using parallel_mode = TRUE is strongly recommended for large stands or fine ray discretisation, as computation time scales almost linearly with the number of available CPU cores.
n_threads	integer or NULL. Number of CPU threads to use when parallel_mode = TRUE. If NULL (default), OpenMP automatically selects the number of available cores. If provided, must be a positive integer.
verbose	Logical; if TRUE, informative messages are printed.

Details

It is the standard user interface of SamsaRaLight. Advanced ray-tracing and sky discretization parameters are internally set to robust defaults and do not need to be provided.

Internally, run_sl() calls the advanced engine run_sl_advanced() with fixed ray-tracing and sky discretization.

You should normally not use SamsaRaLight:::run_sl_advanced() directly unless you are developing new ray-tracing configurations or doing methodological work.

Value

An object of class "sl_output", containing:

light

A list of data.frames with simulated light interception:

• trees: light intercepted by trees

• cells: light received by ground cells

• sensors: light received by sensors

info

A list of metadata about the simulation (latitude, sky type, torus use, etc.).

monthly_rays

(only if detailed_output = TRUE) Discretization of monthly radiations

interceptions

(only if detailed_output = TRUE) interception matrices between trees and rays for each cell/sensor

See Also

create_sl_stand, check_inventory, check_sensors, get_monthly_radiations, check_monthly_radiations

Examples

data_prenovel <- SamsaRaLight::data_prenovel

stand <- create_sl_stand(
  trees = data_prenovel$trees,
  sensors = data_prenovel$sensors,
  cell_size = 10,
  latitude = data_prenovel$info$latitude,
  slope = data_prenovel$info$slope,
  aspect = data_prenovel$info$aspect,
  north2x = data_prenovel$info$north2x
)

out <- run_sl(
  sl_stand = stand,
  monthly_radiations = data_prenovel$radiations
)

str(out)

---

Compute advanced SamsaRaLight radiative balance

Description

This function runs the full light interception and radiative balance simulation for a virtual forest stand with advanced parameters. It allows customization of ray discretization, sky type and trunk interception.

Usage

run_sl_advanced(
  sl_stand,
  monthly_radiations,
  sensors_only = FALSE,
  use_torus = TRUE,
  turbid_medium = TRUE,
  extinction_coef = 0.5,
  clumping_factor = 1,
  trunk_interception = TRUE,
  height_anglemin = 10,
  direct_startoffset = 0,
  direct_anglestep = 5,
  diffuse_anglestep = 15,
  soc = TRUE,
  start_day = 1,
  end_day = 365,
  detailed_output = FALSE,
  parallel_mode = FALSE,
  n_threads = NULL,
  verbose = TRUE
)

Arguments

sl_stand	An object of class "sl_stand" representing the virtual stand. Each row is a tree with required and optional columns describing crown geometry, height, crown radius, crown openness, LAD, etc. See validate_sl_stand.
monthly_radiations	data.frame of monthly horizontal radiation (Hrad) and diffuse to global ratio (DGratio), computed with get_monthly_radiations.
sensors_only	logical, if TRUE, compute interception only for sensors
use_torus	logical, if TRUE, use torus system for borders
turbid_medium	logical, if TRUE, crowns are considered turbid medium (using column crown_lad), else porous envelope (using column crown_openess)
extinction_coef	Numeric scalar. Leaf extinction coefficient controlling the probability that a ray is intercepted by foliage. It represents the effective light attenuation per unit leaf area and is linked to average leaf orientation. Higher values increase interception (default = 0.5).
clumping_factor	Numeric scalar controlling the aggregation of leaves within the crown volume. A value of 1 corresponds to a homogeneous (random) foliage distribution; values < 1 indicate clumped foliage, and values > 1 indicate more regular spacing. This modifies effective light interception in the turbid medium model (default = 1).
trunk_interception	logical, if TRUE, account for trunk interception
height_anglemin	numeric, minimum altitude angle for rays (degrees)
direct_startoffset	numeric, starting angle of first direct ray (degrees)
direct_anglestep	numeric, hour angle step between direct rays (degrees)
diffuse_anglestep	numeric, hour angle step between diffuse rays (degrees)
soc	logical, if TRUE, use Standard Overcast Sky; if FALSE, Uniform Overcast Sky
start_day	integer, first day of the vegetative period (1–365)
end_day	integer, last day of the vegetative period (1–365)
detailed_output	logical, if TRUE, include detailed rays, energies, and interception matrices
parallel_mode	logical. If TRUE, ray–target computations are parallelised using OpenMP. If FALSE, the model runs in single-thread mode.
n_threads	integer or NULL. Number of CPU threads to use when parallel_mode = TRUE. If NULL (default), OpenMP automatically selects the number of available cores. If provided, must be a positive integer.
verbose	Logical; if TRUE, informative messages are printed.

Details

For typical use, see the simpler run_sl wrapper that sets standard discretization parameters for most users.

This advanced function exposes all ray tracing parameters and is intended for users who need full control over ray discretization and modeling options. For most users, see run_sl which wraps this function with default parameters suitable for standard runs.

Value

An object of class "sl_output" (list) containing:

• light: list with simulation outputs for trees, cells, and sensors

• info: list with run metadata (latitude, days, sky type, etc.)

• monthly_rays (if detailed_output = TRUE): ray discretization per month

• interceptions (if detailed_output = TRUE): tree/cell interception matrices

---

Example forest inventory datasets for SamsaRaLight

Description

These datasets provide example forest inventories used for light interception simulations with the SamsaRaLight package. Each dataset is a named list with 5 elements: trees, sensors, core_polygon, radiations, and info.

Usage

data(data_prenovel)
data(data_IRRES1)
data(data_bechefa)
data(data_cloture20)

data_prenovel

data_IRRES1

data_bechefa

data_cloture20

Format

A named list with 5 elements:

trees

A data.frame with tree-level data:

id_tree

Unique id of the tree (integer).

species

Latin species name (character).

x, y

Coordinates of the base of the tree in meters (numeric).

dbh_cm

Diameter at breast height in cm (numeric).

crown_type

Crown shape type, e.g. "P", "E", or complex types like "8E" (character).

h_m

Height of the tree trunk in meters (numeric).

hbase_m

Height of crown base in meters (numeric).

hmax_m

Height at which crown radius is maximum, NA if not used (numeric).

rn_m, rs_m, re_m, rw_m

Crown radii in meters (numeric).

crown_lad

Leaf area density of the crown (m2/m3) (numeric).

sensors

A data.frame with sensor data:

id_sensor

Unique sensor ID (integer).

x, y

Coordinates of the sensor in meters (numeric).

h_m

Height of the sensor in meters (numeric).

pacl, pacl_direct, pacl_diffuse

Proportion of above-canopy light measured at the sensor (numeric).

May be NULL if no sensors are present.

core_polygon

A data.frame with vertices of the inventory polygon:

x, y

Coordinates of polygon vertices in meters (numeric).

radiations

A data.frame of monthly radiation:

month

Month number (integer).

Hrad

Monthly radiation in MJ (numeric).

DGratio

Diffuse-to-global radiation ratio (numeric).

info

A named list with site information:

latitude, longitude

Coordinates of the site in decimal degrees (numeric).

slope

Mean slope in degrees (numeric).

aspect

Aspect in degrees from north (numeric).

north2x

Angle from north to x-axis clockwise in degrees (numeric).

An object of class list of length 5.

An object of class list of length 5.

An object of class list of length 5.

An object of class list of length 5.

Source

Courbaud Benoit (INRAe LESSEM Grenoble)

Gauthier Ligot (Gembloux Agro-Bio Tech)

Gauthier Ligot (Gembloux Agro-Bio Tech)

Gauthier Ligot (Gembloux Agro-Bio Tech)

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Summary of a SamsaRaLight simulation

Description

Summary of a SamsaRaLight simulation

Usage

## S3 method for class 'sl_output'
summary(object, ...)

Arguments

object	an object of class sl_output
...	unused

Value

A list containing summary statistics of the simulation output, including tree-level intercepted light and stand-level incident light.

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Summary of a SamsaRaLight stand

Description

Summary of a SamsaRaLight stand

Usage

## S3 method for class 'sl_stand'
summary(object, ...)

Arguments

object	A sl_stand object
...	Unused

Value

Invisibly returns a list of summary tables

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