Title:	Simulate Fractal Trees and Forests
Version:	1.0.1
Description:	Create and visualize fractal trees and fractal forests, based on the Lindenmayer system (L-system). For more details see Lindenmayer (1968a) <doi:10.1016/0022-5193(68)90079-9> and Lindenmayer (1968b) <doi:10.1016/0022-5193(68)90080-5>.
License:	MIT + file LICENSE
Encoding:	UTF-8
RoxygenNote:	7.2.3
Imports:	dplyr, purrr, stringi, stringr, magrittr, ggplot2, cowplot, sf, rlang, stats, utils
Suggests:	knitr, rmarkdown, spelling, forestmangr, patchwork
VignetteBuilder:	knitr
Language:	en-US
NeedsCompilation:	no
Packaged:	2025-07-02 17:40:41 UTC; sergio.costa
Author:	Sergio Costa [aut, cre, cph], Gilmara Machado [aut, cph]
Maintainer:	Sergio Costa <sergio.vscf@gmail.com>
Repository:	CRAN
Date/Publication:	2025-07-02 18:40:01 UTC

fractalforest: Simulate Fractal Trees and Forests

Description

Create and visualize fractal trees and fractal forests, based on the Lindenmayer system (L-system). For more details see Lindenmayer (1968a) doi:10.1016/0022-5193(68)90079-9 and Lindenmayer (1968b) doi:10.1016/0022-5193(68)90080-5.

Author(s)

Maintainer: Sergio Costa sergio.vscf@gmail.com (ORCID) [copyright holder]

Authors:

• Gilmara Machado gmachado@unicentro.br (ORCID) [copyright holder]

Construct a 2D Forest Profile Using L-System Trees from Inventory Data.

Description

Construct a 2D Forest Profile Using L-System Trees from Inventory Data.

Usage

build_forest_profile(
  data,
  height,
  diameter,
  label,
  string = NULL,
  tree_model = "binary_tree",
  n_iter = NULL,
  angle = 15,
  crown_diameter = NULL,
  h_reduction = (1 + sqrt(5))/2 - 1,
  d_reduction = (1 + sqrt(5))/2 - 1,
  randomness = FALSE,
  angle_cv = 0.1,
  length_cv = 0.1,
  leaf_size = NULL,
  sample = TRUE,
  n_trees,
  dist = 3,
  dist_cv = 0
)

Arguments

Details

• When string is specified, it must be a column in data containing turtle graphics strings for each tree.

• If sample is TRUE, n_trees must be provided.

Value

A data frame containing the 2D forest profile data, with individual tree id, component coordinates, component types, labels and diameters.

Examples

# Example data
data <- data.frame(
  height = c(10, 12, 14, 12, 18, 15, 13, 16, 10, 8, 10, 7),
  diameter = c(12, 15, 11, 17, 25, 18, 10, 21, 12, 10, 10, 11),
  label = c("Tree1", "Tree2", "Tree3","Tree4", "Tree5", "Tree6",
            "Tree7", "Tree8", "Tree9", "Tree10", "Tree11", "Tree12")
)

# Build forest profile
build_forest_profile(
  data = data,
  height = height,
  diameter = diameter,
  label = label,
  tree_model = "binary_tree",
  n_trees = 3
)

Build a 2D L-System Tree Using Turtle Graphics

Description

This function generates a 2D representation of a tree using L-system string instructions and turtle graphics. The tree structure is determined by the L-system string, and various parameters control the shape, size, and randomness of the tree's growth.

Usage

build_tree(
  string = NULL,
  angle = 15,
  height = NULL,
  diameter = NULL,
  crown_diameter = NULL,
  h_reduction = (1 + sqrt(5))/2 - 1,
  d_reduction = (1 + sqrt(5))/2 - 1,
  randomness = FALSE,
  angle_cv = 0.1,
  length_cv = 0.1,
  leaf_size = NULL
)

Arguments

Value

A data frame containing the 2D tree profile data (component coordinates and types).

Build a 2D L-System Tree from Predefined Tree Templates

Description

This function generates 2D L-system trees using predefined templates. Each template is based on a specific tree model, and the function allows you to control the number of iterations to generate the desired tree structure.

Usage

fractal_tree_model(tree_model, n_iter)

Arguments

Details

This function uses a set of predefined L-system rules to generate the tree structure. The rules for each tree model are stored in the rules data frame. The default number of iterations (n_iter) for each tree model is specified in the list above. If n_iter is not provided, the default value for the selected tree model will be used.

Value

A list representing the L-system tree structure after applying the specified number of iterations.

Generate a Point Cloud from 2D trees data frame

Description

This function generates a point cloud based on the geometry of a tree or forest profile.

Usage

generate_point_cloud(tree_df, pt_distance = 0.3)

Arguments

Details

This function processes the input tree_df by creating lines from the tree's geometry and then buffers these lines to account for the tree's diameter. A grid is then created over the buffered geometry, and points are generated where the grid intersects the geometry. The result is a point cloud of 2D coordinates representing the tree's profile.

Value

A matrix of 2D coordinates representing the point cloud. Each row corresponds to a point in the cloud, with the columns representing the X and Y coordinates.

Extract the Fractal Tree Matrix from a Tree Data Frame

Description

Extract the Fractal Tree Matrix from a Tree Data Frame

Usage

get_tree_matrix(tree_df)

Arguments

Details

This function extracts the start and end coordinates of the tree segments and returns the result as a matrix.

Value

A matrix of unique coordinates (x, y) representing the positions of the tree's segments.

Check if character is a branch symbol

Description

Check if character is a branch symbol

Usage

is_branch_symbol(x)

Arguments

Value

A logical vector the same length as x, with TRUE for elements that are not one of the branch symbols ("[", "]", "+", "-", "(", ")", "<", ">"), and FALSE otherwise.

Check if character is a pop symbol

Description

Check if character is a pop symbol

Usage

is_pop_symbol(x)

Arguments

Value

A logical vector the same length as x, with TRUE for elements equal to the pop symbol "]", and FALSE otherwise.

Rewrite an Axiom Using Production Rules to Generate a String for Turtle Graphics

Description

This function iterates over a set of production rules to transform an initial axiom (a string) into a final string that can be used for turtle graphics. The rules are applied to the axiom over a specified number of iterations, with each iteration updating the string according to the rules provided.

Usage

iterate_lsystem(init = NULL, rules = NULL, n_iter = 5, verbose = 0L)

Arguments

Details

The function applies the provided production rules to the initial axiom for the specified number of iterations. In each cycle, the rules are applied simultaneously to the current string, and the resulting string is updated. The function also supports different verbosity levels for reporting the transformation progress.

Value

A character string that represents the final string after all iterations, ready for use in turtle graphics.

Examples

# Example of a simple L-system with a binary tree
init <- "0"
rules <- data.frame(
  inp = c("0", "1"),
  out = c("1[-(0)]+(0)", "1"),
  stringsAsFactors = FALSE
)
result <- iterate_lsystem(init, rules, n_iter = 3, verbose = 1L)
print(result)

Visualize the 2D profile of a fractal trees forest

Description

This function generates a 2D visualization of the forest profile using data from a fractal trees. The forest is plotted with tree branches and leaves. The user can customize the appearance using different parameters.

Usage

plot_forest_profile(
  tree_df,
  d_col = NULL,
  branch_color = "black",
  leaf_color = "black",
  label = NULL,
  label_size = 4,
  simplify = FALSE,
  dTolerance = 0.15
)

Arguments

Value

A ggplot object representing the forest profile.

Visualize a fractal tree

Description

This function generates a visualization of a fractal tree based on the geometry and attributes from the build_tree function. The tree is plotted with branches and leaves. The user can customize the appearance using various parameters.

Usage

plot_tree(
  tree_df,
  d_col = NULL,
  branch_color = "black",
  leaf_color = "black",
  simplify = FALSE,
  dTolerance = 0.15
)

Arguments

Value

A ggplot object representing the tree profile.