library(WoodSimulatR)
library(magrittr)
library(ggplot2)
pander::panderOptions('knitr.auto.asis', FALSE);
The WoodSimulatR
package provides functions for generating artificial datasets of sawn wood properties obtained by destructive and non-destructive testing.
An existing dataset containing some of these properties can be enriched by adding simulated values for the missing properties.
This document aims to provide an overview of the capabilities of the WoodSimulatR
package.
On the one hand, we will simulate a dataset with varying parameters, highlighting both the capabilities of the WoodSimulatR
functions and the direction where it should go.
On the other hand, we will illustrate the capabilities of WoodSimulatR
with respect to simulating grade determining properties for a dataset with different pre-existing variables.
As a quick summary of each dataset, we will show mean and CoV for all variables, split by country and subsample, and we will show the matrix of correlations.
For this, we define the following function:
summ_fun <- function(ds) {
grp <- c('country', 'subsample', 'loadtype');
grp <- intersect(grp, names(ds));
v <- setdiff(names(ds), grp);
r <- cor(ds[v]);
ds <- tibble::add_column(ds, n = 1);
v <- c('n', v);
ds <- tidyr::gather(ds, 'property', 'value', !!! rlang::syms(v));
ds <- dplyr::mutate(
ds,
property = factor(
property,
levels=v,
labels=ifelse(v=='n', v, paste0(v, '_mean')),
ordered = TRUE
)
);
grp <- c(grp, 'property');
ds <- dplyr::group_by(ds, !!! rlang::syms(grp));
summ <- dplyr::summarise(
ds,
res = if (property[1] == 'n') sprintf('%.0f', sum(value)) else
sprintf(
if(property[1] %in% c('f_mean', 'ip_f_mean')) '%.1f (%.0f)' else '%.0f (%.0f)',
mean(value), 100*sd(value)/mean(value)),
.groups = 'drop_last'
);
pander::pander(
tidyr::spread(summ, property, res),
split.tables = Inf
);
pander::pander(r)
invisible(summ);
}
compare_with_def <- function(ds, ssd, target = c('mean', 'cov')) {
target <- match.arg(target);
ds <- dplyr::group_by(ds, country);
summ <- dplyr::summarise(
ds,
f_mean.ach = mean(f),
f_cov.ach = sd(f) / f_mean.ach,
E_mean.ach = mean(E),
E_cov.ach = sd(E) / E_mean.ach,
rho_mean.ach = mean(rho),
rho_cov.ach = sd(rho) / rho_mean.ach,
.groups = 'drop_last'
);
stopifnot(!anyDuplicated(ssd$country));
summ <- dplyr::left_join(
summ,
dplyr::select(
dplyr::mutate(ssd, f_cov = f_sd / f_mean, E_cov = E_sd / E_mean, rho_cov = rho_sd / rho_mean),
country, f_mean, f_cov, E_mean, E_cov, rho_mean, rho_cov
),
by = 'country'
);
summ <- tidyr::pivot_longer(
summ,
-country,
names_to = c('gdpname', '.value'),
names_sep = '_'
);
summ <- dplyr::mutate(
summ,
gdpname = factor(gdpname, levels = c('f', 'E', 'rho'), ordered = TRUE)
);
if (target == 'mean') {
ggplot(data = summ, aes(mean.ach, mean)) +
geom_abline(slope = 1, intercept = 0) +
geom_text(aes(label = country)) +
geom_point(alpha = 0.5) +
facet_wrap(vars(gdpname), scales = 'free') +
theme(axis.text.x = element_text(angle = 90));
} else {
ggplot(data = summ, aes(cov.ach, cov)) +
geom_abline(slope = 1, intercept = 0) +
geom_text(aes(label = country)) +
geom_point(alpha = 0.5) +
facet_wrap(vars(gdpname), scales = 'free') +
theme(axis.text.x = element_text(angle = 90));
}
}
The main function for dataset simulation is simulate_dataset()
. It can be called without any further arguments to yield a “default” dataset.
For reproducibility, we will call it with the extra argument random_seed = 12345
. This means that we will always generate the same random numbers.
dataset_0 <- simulate_dataset(random_seed = 2345);
#> Warning in RNGkind("Mersenne-Twister", "Inversion", "Rounding"): non-uniform
#> 'Rounding' sampler used
summ_fun(dataset_0);
country | subsample | loadtype | n | f_mean | E_mean | rho_mean | E_dyn_u_mean | ip_f_mean | E_dyn_mean | ip_rho_mean |
---|---|---|---|---|---|---|---|---|---|---|
C1 | C1 | t | 1250 | 26.1 (39) | 10858 (19) | 436 (11) | 10334 (19) | 25.0 (33) | 11704 (18) | 452 (11) |
C2 | C2 | t | 1250 | 26.8 (37) | 11573 (20) | 423 (10) | 10829 (19) | 28.2 (33) | 12160 (19) | 442 (9) |
C3 | C3 | t | 1250 | 31.4 (40) | 10356 (22) | 443 (11) | 10044 (20) | 24.2 (37) | 11367 (20) | 454 (10) |
C4 | C4 | t | 1250 | 25.4 (42) | 10822 (22) | 405 (10) | 10122 (20) | 26.0 (37) | 11357 (20) | 425 (10) |
f | E | rho | E_dyn_u | ip_f | E_dyn | ip_rho | |
---|---|---|---|---|---|---|---|
f | 1 | 0.6938 | 0.332 | 0.6209 | 0.7269 | 0.6518 | 0.3103 |
E | 0.6938 | 1 | 0.5475 | 0.9033 | 0.9099 | 0.9487 | 0.5694 |
rho | 0.332 | 0.5475 | 1 | 0.5953 | 0.3754 | 0.6661 | 0.9417 |
E_dyn_u | 0.6209 | 0.9033 | 0.5953 | 1 | 0.8512 | 0.9416 | 0.6193 |
ip_f | 0.7269 | 0.9099 | 0.3754 | 0.8512 | 1 | 0.883 | 0.3668 |
E_dyn | 0.6518 | 0.9487 | 0.6661 | 0.9416 | 0.883 | 1 | 0.6984 |
ip_rho | 0.3103 | 0.5694 | 0.9417 | 0.6193 | 0.3668 | 0.6984 | 1 |
The meaning of the properties in dataset_0
is as follows:
All properties except E_dyn_u are to be taken as measured on the dry timber and corrected to a moisture content of 12%.
The default dataset created above relies on the following assumptions:
All of these assumptions can be modified more or less freely.
get_subsample_definitions(loadtype = 't') %>%
dplyr::select(-species, -loadtype) %>%
dplyr::arrange(country) %>%
pander::pander(split.table = Inf);
project | country | share | f_mean | f_sd | E_mean | E_sd | rho_mean | rho_sd | literature | subsample |
---|---|---|---|---|---|---|---|---|---|---|
siosip | at | 1 | 29.4 | 11.3 | 11912 | 2232 | 443 | 42.1 | null | at |
gradewood | at | 1 | 25.1 | 10.54 | 10100 | 2626 | 435 | 52.2 | Ranta-Maunus et al. (2011) | at_1 |
gradewood | ch | 1 | 27.8 | 12.23 | 10900 | 2616 | 439 | 52.68 | Ranta-Maunus et al. (2011) | ch |
gradewood | de | 1 | 32.6 | 12.06 | 12100 | 2541 | 451 | 49.61 | Ranta-Maunus et al. (2011) | de |
gradewood | fi | 1 | 33.2 | 11.29 | 11800 | 2242 | 445 | 44.5 | Ranta-Maunus et al. (2011) | fi |
null | lv | 1 | 30.4 | 11.55 | 11700 | 2808 | 466 | 51.26 | Stapel et al. (2014) | lv |
gradewood | pl | 1 | 28.2 | 10.72 | 11600 | 2668 | 452 | 54.24 | Ranta-Maunus et al. (2011) | pl |
gradewood | ro | 1 | 25.6 | 10.75 | 10000 | 2100 | 390 | 31.2 | Ranta-Maunus et al. (2011) | ro |
gradewood | se | 1 | 27.6 | 10.49 | 10200 | 2346 | 416 | 49.92 | Ranta-Maunus et al. (2011) | se |
gradewood | si | 1 | 34 | 14.96 | 12300 | 2706 | 442 | 39.78 | Ranta-Maunus et al. (2011) | si |
gradewood | sk | 1 | 27.2 | 10.88 | 10700 | 2140 | 408 | 36.72 | Ranta-Maunus et al. (2011) | sk |
gradewood | ua | 1 | 26.7 | 11.75 | 10300 | 2163 | 392 | 43.12 | Ranta-Maunus et al. (2011) | ua |
get_subsample_definitions(loadtype = 'be') %>%
dplyr::select(-species, -loadtype) %>%
dplyr::arrange(country) %>%
pander::pander(split.table = Inf);
project | country | share | f_mean | f_sd | E_mean | E_sd | rho_mean | rho_sd | literature | subsample |
---|---|---|---|---|---|---|---|---|---|---|
siosip | at | 1 | 41.4 | 12.7 | 12294 | 2636 | 436 | 39.9 | null | at |
gradewood | de | 1 | 41.5 | 14.11 | 12100 | 3146 | 441 | 48.51 | Ranta-Maunus et al. (2011) | de |
gradewood | fr | 1 | 42.9 | 11.15 | 11900 | 2023 | 440 | 44 | Ranta-Maunus et al. (2011) | fr |
gradewood | pl | 1 | 38.5 | 11.94 | 11400 | 2280 | 440 | 48.4 | Ranta-Maunus et al. (2011) | pl |
gradewood | ro | 1 | 35.5 | 11.01 | 9600 | 1824 | 387 | 38.7 | Ranta-Maunus et al. (2011) | ro |
gradewood | se | 1 | 42.5 | 14.87 | 11300 | 2486 | 435 | 52.2 | Ranta-Maunus et al. (2011) | se |
gradewood | se | 1 | 44.8 | 13.44 | 12300 | 2706 | 435 | 52.2 | Ranta-Maunus et al. (2011) | se_1 |
gradewood | si | 1 | 43.7 | 13.11 | 12000 | 2400 | 445 | 44.5 | Ranta-Maunus et al. (2011) | si |
gradewood | sk | 1 | 34.8 | 11.48 | 10200 | 2040 | 415 | 41.5 | Ranta-Maunus et al. (2011) | sk |
null | sk | 1 | 41 | 11.89 | 12252 | 2328 | 434 | 39.06 | Rohanova (2014) | sk_1 |
gradewood | ua | 1 | 36.2 | 10.5 | 10000 | 1900 | 389 | 38.9 | Ranta-Maunus et al. (2011) | ua |
ssd_c <- get_subsample_definitions(
country = c('at', 'de', 'fi', 'pl', 'se', 'si', 'sk'),
loadtype = 't'
);
dataset_c <- simulate_dataset(
random_seed = 12345,
n = 5000,
subsets = ssd_c
);
#> Warning in RNGkind("Mersenne-Twister", "Inversion", "Rounding"): non-uniform
#> 'Rounding' sampler used
summ_fun(dataset_c);
country | subsample | loadtype | n | f_mean | E_mean | rho_mean | E_dyn_u_mean | ip_f_mean | E_dyn_mean | ip_rho_mean |
---|---|---|---|---|---|---|---|---|---|---|
at | at | t | 714 | 29.4 (38) | 11982 (19) | 443 (10) | 11184 (18) | 29.4 (31) | 12678 (17) | 459 (9) |
de | de | t | 715 | 32.6 (37) | 12021 (21) | 450 (12) | 11266 (20) | 29.9 (33) | 12811 (19) | 464 (11) |
fi | fi | t | 714 | 33.2 (34) | 11755 (19) | 445 (9) | 11062 (18) | 29.3 (30) | 12541 (17) | 458 (9) |
pl | pl | t | 714 | 28.2 (38) | 11573 (23) | 451 (12) | 10943 (21) | 27.6 (37) | 12417 (21) | 465 (11) |
se | se | t | 714 | 27.6 (38) | 10239 (23) | 415 (12) | 9814 (22) | 24.0 (38) | 11004 (21) | 432 (11) |
si | si | t | 715 | 34.0 (44) | 12352 (22) | 442 (9) | 11510 (20) | 31.1 (35) | 13022 (19) | 459 (8) |
sk | sk | t | 714 | 27.2 (40) | 10587 (19) | 406 (9) | 9946 (18) | 25.3 (33) | 11194 (18) | 425 (9) |
f | E | rho | E_dyn_u | ip_f | E_dyn | ip_rho | |
---|---|---|---|---|---|---|---|
f | 1 | 0.7486 | 0.3253 | 0.6655 | 0.7819 | 0.6867 | 0.31 |
E | 0.7486 | 1 | 0.6452 | 0.919 | 0.9217 | 0.9593 | 0.6508 |
rho | 0.3253 | 0.6452 | 1 | 0.6738 | 0.4833 | 0.7334 | 0.9474 |
E_dyn_u | 0.6655 | 0.919 | 0.6738 | 1 | 0.8739 | 0.9526 | 0.6865 |
ip_f | 0.7819 | 0.9217 | 0.4833 | 0.8739 | 1 | 0.9006 | 0.4658 |
E_dyn | 0.6867 | 0.9593 | 0.7334 | 0.9526 | 0.9006 | 1 | 0.7525 |
ip_rho | 0.31 | 0.6508 | 0.9474 | 0.6865 | 0.4658 | 0.7525 | 1 |
Compare achieved means with the defined values. It can be seen that the means of \(f\) are met exactly, while the means of \(E\) and \(rho\) are only met approximately, which is the desideratum when we are dealing with simulation.
Compare achieved coefficients of variation with the defined values. Again, we have undesirable exact values for \(f\).
ssd_cn <- get_subsample_definitions(
country = c(at = 1, de = 3, fi = 1.5, pl = 2, se = 3, si = 1, sk = 1),
loadtype = 't'
);
dataset_cn <- simulate_dataset(
random_seed = 12345,
n = 5000,
subsets = ssd_cn
);
#> Warning in RNGkind("Mersenne-Twister", "Inversion", "Rounding"): non-uniform
#> 'Rounding' sampler used
summ_fun(dataset_cn);
country | subsample | loadtype | n | f_mean | E_mean | rho_mean | E_dyn_u_mean | ip_f_mean | E_dyn_mean | ip_rho_mean |
---|---|---|---|---|---|---|---|---|---|---|
at | at | t | 400 | 29.4 (38) | 12189 (19) | 444 (10) | 11320 (18) | 30.1 (30) | 12815 (17) | 460 (9) |
de | de | t | 1200 | 32.6 (37) | 12102 (21) | 451 (11) | 11302 (19) | 30.2 (33) | 12861 (19) | 464 (11) |
fi | fi | t | 600 | 33.2 (34) | 11838 (18) | 445 (10) | 11116 (18) | 29.7 (30) | 12600 (17) | 459 (9) |
pl | pl | t | 800 | 28.2 (38) | 11501 (23) | 451 (12) | 10885 (21) | 27.4 (37) | 12378 (21) | 465 (11) |
se | se | t | 1200 | 27.6 (38) | 10206 (23) | 417 (12) | 9769 (22) | 23.9 (39) | 10989 (22) | 432 (11) |
si | si | t | 400 | 34.0 (44) | 12218 (21) | 441 (9) | 11326 (19) | 30.7 (34) | 12801 (19) | 457 (9) |
sk | sk | t | 400 | 27.2 (40) | 10716 (19) | 407 (9) | 10042 (18) | 26.0 (32) | 11301 (18) | 426 (9) |
f | E | rho | E_dyn_u | ip_f | E_dyn | ip_rho | |
---|---|---|---|---|---|---|---|
f | 1 | 0.7386 | 0.3347 | 0.6617 | 0.7733 | 0.68 | 0.3249 |
E | 0.7386 | 1 | 0.6581 | 0.9214 | 0.9231 | 0.9601 | 0.6675 |
rho | 0.3347 | 0.6581 | 1 | 0.6852 | 0.4949 | 0.7485 | 0.9523 |
E_dyn_u | 0.6617 | 0.9214 | 0.6852 | 1 | 0.8715 | 0.9547 | 0.6991 |
ip_f | 0.7733 | 0.9231 | 0.4949 | 0.8715 | 1 | 0.8985 | 0.4798 |
E_dyn | 0.68 | 0.9601 | 0.7485 | 0.9547 | 0.8985 | 1 | 0.7673 |
ip_rho | 0.3249 | 0.6675 | 0.9523 | 0.6991 | 0.4798 | 0.7673 | 1 |
simbase_covar()
For adding simulated values to a dataset, we first need to establish the relationship between these values and some variables in the dataset.
In WoodSimulatR
, relationships are established in the following way:
simbase_covar()
; the resulting simbase has class “simbase_covar”.simbase_covar()
; the resulting simbase has class “simbase_list”.For both these options, it is possible to transform the involved variables.
To visualise the result of the simulation, we use scatterplots and define them in the following function:
plot_sim_gdp <- function(ds, simb, simulated_vars, ...) {
extra_aes <- rlang::enexprs(...);
ds <- dplyr::rename(ds, f_ref = f, E_ref = E, rho_ref = rho);
if (!any(simulated_vars %in% names(ds))) ds <- simulate_conditionally(data = ds, simbase = simb);
ds <- tidyr::pivot_longer(
data = ds,
cols = tidyselect::any_of(c('f_ref', 'E_ref', 'rho_ref', simulated_vars)),
names_to = c('name', '.value'),
names_sep = '_'
);
ds <- dplyr::mutate(
ds,
name = factor(name, levels = c('f', 'E', 'rho'), ordered = TRUE)
);
simname <- names(ds);
simname <- simname[dplyr::cumany(simname == 'name')];
simname <- setdiff(simname, c('name', 'ref'));
stopifnot(length(simname) == 1);
ggplot(data = ds, mapping = aes(.data[[simname]], ref, !!!extra_aes)) +
geom_point(alpha = .2, shape = 20) +
geom_abline(slope = 1, intercept = 0, alpha = .5, linetype = 'twodash') +
facet_wrap(vars(name), scales = 'free') +
theme(axis.text.x = element_text(angle = 90));
} # undebug(plot_sim_gdp)
simbase_covar
without transformationThe main approach in WoodSimulatR
is to conditionally simulate based on the means and the covariance matrix. As a start, we create basis data for the simulation without applying any transformation.
As we later want to add simulated GDP values to a dataset which already contains GDP values, we rename the GDP values for the simbase_covar
to some other names not yet present in the target dataset, by suffixing with _siml
(for SIMulation with Linear relationships)
sb_untransf <- dataset_0 %>%
dplyr::rename(f_siml = f, E_siml = E, rho_siml = rho) %>%
simbase_covar(
variables = c('f_siml', 'E_siml', 'rho_siml', 'ip_f', 'E_dyn', 'ip_rho')
);
sb_untransf;
#> $label
#> [1] "n5000_t_cov"
#>
#> $variables
#> [1] "f_siml" "E_siml" "rho_siml" "ip_f" "E_dyn" "ip_rho"
#>
#> $transforms
#> list()
#>
#> $covar
#> f_siml E_siml rho_siml ip_f E_dyn ip_rho
#> f_siml 123.48879 17833.53 176.0599 74.39333 16294.87 157.3809
#> E_siml 17833.52632 5350561.53 60442.9207 19384.22862 4936929.13 60112.9581
#> rho_siml 176.05989 60442.92 2277.8973 165.03216 71523.40 2051.2843
#> ip_f 74.39333 19384.23 165.0322 84.82026 18296.48 154.1760
#> E_dyn 16294.87244 4936929.13 71523.3978 18296.48185 5061578.82 71714.5604
#> ip_rho 157.38089 60112.96 2051.2843 154.17601 71714.56 2083.1286
#>
#> $means
#> f_siml E_siml rho_siml ip_f E_dyn ip_rho
#> 27.44698 10902.33238 426.68168 25.84706 11646.95452 443.01789
#>
#> $loadtype
#> [1] "t"
#>
#> attr(,"class")
#> [1] "simbase_covar"
Adding the simulated GDP values to a dataset is done by calling simulate_conditionally()
.
dataset_c_sim <- simulate_conditionally(dataset_c, sb_untransf);
names(dataset_c_sim) %>% pander::pander();
f, E, rho, country, subsample, E_dyn_u, ip_f, E_dyn, ip_rho, loadtype, f_siml, E_siml and rho_siml
For a visual comparison:
This looks good for \(E\) and \(\rho\), but wrong in the \(f\) simulation.
simbase_covar
with log-transformed \(f\)We might try using transforms
to improve the result. For this, we have to pass a list with named entries corresponding to the GDP we want to transform.
The entry itself must be an object of class "trans"
(from the package scales
). As we want to use a log-transform, the required entry is scales::log_trans()
.
sb_transf <- dataset_0 %>%
dplyr::rename(f_simt = f, E_simt = E, rho_simt = rho) %>%
simbase_covar(
variables = c('f_simt', 'E_simt', 'rho_simt', 'ip_f', 'E_dyn', 'ip_rho'),
transforms = list(f_simt = scales::log_trans())
);
dataset_c_sim <- simulate_conditionally(dataset_c_sim, sb_transf);
plot_sim_gdp(dataset_c_sim, sb_transf, c('f_simt', 'E_simt', 'rho_simt'));
Now, this looks much better (which is no surprise, as dataset_c
itself has been simulated with lognormal \(f\)).
simbase_covar
with log-transformed \(f\) and derived on a grouped datasetIf we group the reference dataset (dataset_0
), e.g. by country, we get an object of class “simbase_list” with separate simbases for each group (technically, this is a tibble
with the grouping variables and an extra column .simbase
which contains several objects of class “simbase_covar”).
sb_group <- dataset_0 %>%
dplyr::group_by(country) %>%
dplyr::rename(f_simg = f, E_simg = E, rho_simg = rho) %>%
simbase_covar(
variables = c('f_simg', 'E_simg', 'rho_simg', 'ip_f', 'E_dyn', 'ip_rho'),
transforms = list(f_simg = scales::log_trans())
);
sb_group
#> # A tibble: 4 x 2
#> country .simbase
#> <chr> <list>
#> 1 C1 <smbs_cvr>
#> 2 C2 <smbs_cvr>
#> 3 C3 <smbs_cvr>
#> 4 C4 <smbs_cvr>
If we add variables to a dataset using such a “simbase_list”, it is required that all grouping variables stored in the “simbase_list” object are also available in this dataset.
In our case: the dataset must contain the variable “country”. Values of “country” which do not also exist in our “simbase” object will result in NA
values for the variables to be simulated.
Therefore, we add the variables in this case not to the dataset dataset_c
(which has different values for “country”) but to the dataset_0
itself.
dataset_0_sim <- simulate_conditionally(dataset_0, sb_group);
plot_sim_gdp(dataset_0_sim, sb_group, c('f_simg', 'E_simg', 'rho_simg'), colour=country);
simbase_list
objectSimbase objects of class “simbase_list” can also be used for simulating an entire dataset, as long as the “simbase_list” only has the grouping variable(s) “country” and/or “subsample”, and as long as the value combinations in “country”/“subsample” match those given in the “subsets” argument to the function simulate_dataset
.
To demonstrate, we calculate a “simbase_list” based on the dataset_c
created above. Here, we do not rename any of the variables.
sb_group_c <- dataset_c %>%
dplyr::group_by(country) %>%
simbase_covar(
variables = c('f', 'E', 'rho', 'ip_f', 'E_dyn', 'ip_rho'),
transforms = list(f = scales::log_trans())
);
sb_group_c
#> # A tibble: 7 x 2
#> country .simbase
#> <chr> <list>
#> 1 at <smbs_cvr>
#> 2 de <smbs_cvr>
#> 3 fi <smbs_cvr>
#> 4 pl <smbs_cvr>
#> 5 se <smbs_cvr>
#> 6 si <smbs_cvr>
#> 7 sk <smbs_cvr>
This “simbase_list” is now used as input to simulate_dataset
with the subset definitions used previously (ssd_cn
).
dataset_cn2 <- simulate_dataset(
random_seed = 12345,
n = 5000,
subsets = ssd_cn,
simbase = sb_group_c
);
#> Warning in RNGkind("Mersenne-Twister", "Inversion", "Rounding"): non-uniform
#> 'Rounding' sampler used
summ_fun(dataset_cn2);
country | subsample | loadtype | n | f_mean | E_mean | rho_mean | ip_f_mean | E_dyn_mean | ip_rho_mean |
---|---|---|---|---|---|---|---|---|---|
at | at | t | 400 | 29.4 (38) | 12190 (19) | 444 (10) | 29.9 (30) | 12844 (17) | 460 (9) |
de | de | t | 1200 | 32.6 (37) | 12122 (20) | 450 (11) | 30.2 (31) | 12891 (19) | 465 (11) |
fi | fi | t | 600 | 33.2 (34) | 11903 (19) | 445 (10) | 29.7 (29) | 12698 (18) | 459 (10) |
pl | pl | t | 800 | 28.2 (38) | 11620 (24) | 451 (12) | 27.8 (39) | 12459 (22) | 465 (11) |
se | se | t | 1200 | 27.6 (38) | 10196 (22) | 417 (12) | 23.9 (37) | 10983 (20) | 433 (11) |
si | si | t | 400 | 34.0 (44) | 12466 (22) | 442 (9) | 31.6 (34) | 13100 (19) | 460 (8) |
sk | sk | t | 400 | 27.2 (40) | 10563 (21) | 406 (9) | 25.5 (36) | 11245 (19) | 426 (9) |
f | E | rho | ip_f | E_dyn | ip_rho | |
---|---|---|---|---|---|---|
f | 1 | 0.7467 | 0.3238 | 0.7827 | 0.6814 | 0.3103 |
E | 0.7467 | 1 | 0.6582 | 0.9221 | 0.9601 | 0.6651 |
rho | 0.3238 | 0.6582 | 1 | 0.4939 | 0.7474 | 0.9515 |
ip_f | 0.7827 | 0.9221 | 0.4939 | 1 | 0.8992 | 0.4804 |
E_dyn | 0.6814 | 0.9601 | 0.7474 | 0.8992 | 1 | 0.767 |
ip_rho | 0.3103 | 0.6651 | 0.9515 | 0.4804 | 0.767 | 1 |
The package WoodSimulatR
has functions for simulating entire datasets of sawn timber properties, both based on internal definitions and on externally supplied base data.
WoodSimulatR
also has functions for adding simulated grade determining properties (or other properties) to a given dataset, based on a covariance matrix approach.
The functions for adding simulated variables are suitable for all kinds of datasets, if one calculates an appropriate simbase_covar
object oneself, by a call to simbase_covar
using reference data.
The simulation methods also support variable transformations to accommodate non-normally distributed variables.