Retrieves the trained lambda (weight) coefficients from the output of
maxent_run, returning them as a named numeric vector.
Each element is the lambda value for the corresponding feature, and the
name of each element is the feature name (e.g. "bio1",
"bio1^2", "bio1'1").
Arguments
- run_result
A named list as returned by
maxent_run. Must contain an elementmodelholding the trained FeaturedSpace external pointer.
Value
A named numeric vector of lambda values, one per feature. Names are the feature names as stored in the model.
Details
The function reads lambdas directly from the trained model object, so
it also works correctly after reloading coefficients with
maxent_load_lambdas.
Examples
# \donttest{
if (requireNamespace("terra", quietly = TRUE)) {
stack_path <- system.file("extdata", "stack_1_12_crop.rds",
package = "maxentcpp")
example_rasters <- terra::unwrap(readRDS(stack_path))
grids <- list(
bio1 = maxent_grid_from_terra(example_rasters[[1]]),
bio12 = maxent_grid_from_terra(example_rasters[[2]])
)
data(example_occ_df)
result <- maxent_run(
species = "Abeillia_abeillei",
env_grids = grids,
occ_df = example_occ_df,
output_dir = tempdir(),
lon_col = "long",
lat_col = "lat")
lambdas <- maxent_extract_lambdas(result)
print(lambdas)
}
#> class : MaxEnt
#> species : Abeillia_abeillei
#> n presence : 73
#> n background : 2371
#>
#> Training statistics
#> AUC : 0.8033
#> Gain : 7.2290
#> Entropy : 7.3714
#>
#> Variable contributions
#> Variable Contribution (%) Permutation importance (%)
#> bio1 61.3 54.0
#> bio12 38.7 46.0
#>
#> bio1_linear bio1_quadratic bio1_hinge_fwd_1 bio1_hinge_rev_1
#> 0.00000000 0.00000000 0.00000000 0.00000000
#> bio1_hinge_fwd_2 bio1_hinge_rev_2 bio1_hinge_fwd_3 bio1_hinge_rev_3
#> 0.00000000 0.00000000 0.00000000 0.00000000
#> bio1_hinge_fwd_4 bio1_hinge_rev_4 bio1_hinge_fwd_5 bio1_hinge_rev_5
#> 0.00000000 0.00000000 0.00000000 -2.92570617
#> bio1_hinge_fwd_6 bio1_hinge_rev_6 bio1_hinge_fwd_7 bio1_hinge_rev_7
#> 0.00000000 -4.54172243 0.00000000 0.00000000
#> bio1_hinge_fwd_8 bio1_hinge_rev_8 bio1_hinge_fwd_9 bio1_hinge_rev_9
#> 0.00000000 0.00000000 0.00000000 0.00000000
#> bio1_hinge_fwd_10 bio1_hinge_rev_10 bio1_hinge_fwd_11 bio1_hinge_rev_11
#> -1.48324905 0.00000000 -2.30675721 0.00000000
#> bio1_hinge_fwd_12 bio1_hinge_rev_12 bio1_hinge_fwd_13 bio1_hinge_rev_13
#> 0.00000000 0.00000000 0.00000000 0.00000000
#> bio1_hinge_fwd_14 bio1_hinge_rev_14 bio1_hinge_fwd_15 bio1_hinge_rev_15
#> 0.00000000 0.00000000 0.00000000 0.00000000
#> bio12_linear bio12_quadratic bio12_hinge_fwd_1 bio12_hinge_rev_1
#> 0.00000000 0.00000000 0.00000000 -2.17821403
#> bio12_hinge_fwd_2 bio12_hinge_rev_2 bio12_hinge_fwd_3 bio12_hinge_rev_3
#> 0.00000000 -2.63658197 0.00000000 0.00000000
#> bio12_hinge_fwd_4 bio12_hinge_rev_4 bio12_hinge_fwd_5 bio12_hinge_rev_5
#> 0.00000000 0.00000000 0.00000000 0.00000000
#> bio12_hinge_fwd_6 bio12_hinge_rev_6 bio12_hinge_fwd_7 bio12_hinge_rev_7
#> 0.00000000 -0.52763351 0.00000000 0.00000000
#> bio12_hinge_fwd_8 bio12_hinge_rev_8 bio12_hinge_fwd_9 bio12_hinge_rev_9
#> 0.00000000 0.00000000 0.00000000 0.00000000
#> bio12_hinge_fwd_10 bio12_hinge_rev_10 bio12_hinge_fwd_11 bio12_hinge_rev_11
#> 0.00000000 0.00000000 0.00000000 0.00000000
#> bio12_hinge_fwd_12 bio12_hinge_rev_12 bio12_hinge_fwd_13 bio12_hinge_rev_13
#> 0.00000000 0.00000000 0.00000000 -0.25879782
#> bio12_hinge_fwd_14 bio12_hinge_rev_14 bio12_hinge_fwd_15 bio12_hinge_rev_15
#> -1.48631046 -0.01083494 0.00000000 0.00000000
# }