| Type: | Package |
| Title: | Provide Functions for Forest Inventory Calculations |
| Version: | 1.1 |
| Date: | 2025-05-15 |
| Description: | Provide functions for forest inventory calculations. Common volumetric equations (Smalian, Newton and Huber) as well stacking factor and form. |
| License: | GPL-3 |
| URL: | https://github.com/dvdscripter/FI |
| BugReports: | https://github.com/dvdscripter/FI/issues |
| NeedsCompilation: | no |
| Packaged: | 2025-05-15 03:15:11 UTC; dvd |
| Author: | David V. Dias [aut, cre] |
| Maintainer: | David V. Dias <dvdscripter@gmail.com> |
| Repository: | CRAN |
| Date/Publication: | 2025-05-15 05:00:06 UTC |
Forest inventory equations and calculations with FI
Description
That package was created because I can't find any free solution for these basic calculations also will serve as learning experience to create packages in R.
Details
Here I implement the three basic volume equations (Smalian, Newton, Huber) and form and stacking factors. From these you can gather many information about a region log volume (mean and standard deviation). Later a new package will provide volumetric equations adjust.
See Also
Factor form for the given volume
Description
This function provide correction for basic volume
estimation using cylinder formulation v =
\frac{DBH^2}{4} \pi H. Factor form
is given by taking ratio between real volume and apparent
volume.
Usage
ff(volume, dbh, height)
Arguments
volume |
volume of a log, can be the output of
|
dbh |
diameter at breast height (1.3 meters from floor) |
height |
commercial height, length of stem or whatever length of log you used in your estimations of cylinder volume |
Value
form factor ranging form 0-1 (numeric value)
References
http://wiki.awf.forst.uni-goettingen.de/wiki/index.php/Stem_shape
Example of how object tree in volume function should be formated
Description
Choice of that format follow similarity with cubmaster for simplify user translation of work (exporting old tables). Names of columns are just cosmetic, currently I use column index. All diameters mensures should rather be in centimeters and heights in meters
Format
A data frame with 17 rows and 6 variables
Details
tree_number. unique number to identify tree information
dbh. diameter at breast height
total_height. total height of the tree. Unsed parameter in
volume-
commercial_height. commercial height of tree. Unsed parameter in
volume section_height. height of each section where diameter section is taken
section_diameter. diameter in current height
Stacking factor
Description
Ratio between solid cubic meters of wood per stere cubic meter of stacked up wood.
Usage
sf(volume, height, length, depth)
Arguments
volume |
real volume of the logs |
height |
height of the stack (in meters) |
length |
length of the stack (in meters) |
depth |
depth of the stack (in meters) |
Value
stacking factor ranging from 0-1
References
https://www.eucalyptus.com.br/capitulos/ENG07.pdf
Estimates the stem volume
Description
volume uses one of the following methods (Smalian,
Newton, Huber) to approximate real stem volume. Users
should remember they're just approximations and sample
size provide more accurate results them using different
methods.
Usage
volume(trees, method = "smalian")
Arguments
trees |
a data frame or matrix in format described
in dataset inventory (more help |
method |
method used for estimation of the stem volume |
Value
a named vector of volumes, names are defined as same as in first column
Note
Newton and Huber methods have small modifications for working just with two mensures (lower and upper diameter). Both of them use mean instead of real middle diameter.
References
http://wiki.awf.forst.uni-goettingen.de/wiki/index.php/Stem_volume
See Also
Examples
example_data <- data.frame(tree_number = 1,
dhb = 5,
total_height = 20,
comercial_height = 15,
section_height = c(0,5,15),
section_diameter = 5
)
volume(example_data)
#
#
# A little more complex and common example
data(inventory)
volume_output <- volume(inventory)
summary(volume_output)
hist(volume_output)