projection_mop: Analysis of extrapolation risks in projections using the MOP...
In kuenm2: Detailed Development of Ecological Niche Models

projection_mop

R Documentation

Analysis of extrapolation risks in projections using the MOP metric

Description

Calculates the mobility-oriented parity metric and other sub-products to represent dissimilarities and non-analogous conditions when comparing a set of reference conditions (M) against model projection conditions (G).

Usage

projection_mop(data, projection_data, out_dir,
               subset_variables = FALSE, mask = NULL, type = "basic",
               na_in_range = TRUE, calculate_distance = FALSE,
               where_distance = "in_range", distance = "euclidean",
               scale = FALSE, center = FALSE, fix_NA = TRUE, percentage = 1,
               comp_each = 2000, tol = NULL, rescale_distance = FALSE,
               parallel = FALSE, ncores = NULL, progress_bar = TRUE,
               overwrite = FALSE)

Arguments

`data`	an object of class `fitted_models` returned by the `fit_selected()` function or an object of class `prepared_data` returned by the `prepare_data()` function.
`projection_data`	an object of class `projection_data` returned by the `prepare_projection()`function. This file contains the paths to the rasters representing each scenario.
`out_dir`	(character) a path to a root directory for saving the raster file of each projection.
`subset_variables`	(logical) whether to include in the analysis only the variables present in the selected models. Only applicable if `data` is a `fitted_models` object. Default is FALSE
`mask`	(SpatRaster, SpatVector, or SpatExtent) spatial object used to mask the variables (optional). Default is NULL.
`type`	(character) type of MOP analysis to be performed. Options available are "basic", "simple" and "detailed". See Details for further information.
`na_in_range`	(logical) whether to assign `NA` to regions within the projected area (G) where environmental conditions fall within the range of the calibration data (M). If `TRUE` (default), these regions are assigned `NA`. If `FALSE`, they are assigned `0` in the simple and basic MOP outputs, and `"within ranges"` in the detailed MOP output.
`calculate_distance`	(logical) whether to calculate distances (dissimilarities) between m and g. The default, FALSE, runs rapidly and does not assess dissimilarity levels.
`where_distance`	(character) where to calculate distances, considering how conditions in g are positioned in comparison to the range of conditions in m. Options available are "in_range", "out_range" and "all". Default is "in_range".
`distance`	(character) which distances are calculated, euclidean or mahalanobis. Only applicable if calculate_distance = TRUE.
`scale`	(logical or numeric) whether to scale as in `scale`. Default is FALSE.
`center`	(logical or numeric) whether to center as in `scale`. Default is FALSE.
`fix_NA`	(logical) whether to fix layers so cells with NA values are the same in all layers. Setting to FALSE may save time if the rasters are big and have no NA matching problems. Default is TRUE.
`percentage`	(numeric) percentage of `m` closest conditions used to derive mean environmental distances to each combination of conditions in `g`.
`comp_each`	(numeric) number of combinations in `g` to be used for distance calculations at a time. Increasing this number requires more RAM
`tol`	(numeric) tolerance to detect linear dependencies when calculating Mahalanobis distances. The default, NULL, uses `.Machine$double.eps`.
`rescale_distance`	(logical) whether to re-scale distances 0-1. Re-scaling prevents comparisons of dissimilarity values obtained from runs with different values of `percentage`.
`parallel`	(logical) whether to fit the candidate models in parallel. Default is FALSE.
`ncores`	(numeric) number of cores to use for parallel processing. Default is NULL and uses available cores - 1. This is only applicable if `parallel = TRUE`.
`progress_bar`	(logical) whether to display a progress bar during processing. Default is TRUE.
`overwrite`	(logical) whether to overwrite SpatRaster if they already exists. Only applicable if `write_files` is set to TRUE. Default is FALSE.

Details

type options return results that differ in the detail of how non-analogous conditions are identified.

basic - makes calculation as proposed by Owens et al. (2013) doi:10.1016/j.ecolmodel.2013.04.011.
simple - calculates how many variables in the set of interest are non-analogous to those in the reference set.
detailed - calculates five additional extrapolation metrics. See mop_detailed under Value below for full details.

where_distance options determine what values should be used to calculate dissimilarity

in_range - only conditions inside m ranges
out_range - only conditions outside m ranges
all - all conditions

When the variables used to represent conditions have different units, scaling and centering are recommended. This step is only valid when Euclidean distances are used.

Value

An object of class mop_projections, with the root directory and the dataframe containing the file paths where the results were stored for each scenario. The paths contain the following files:

summary - a data.frame with details of the data used in the analysis:
- variables - names of variables considered.
- type - type of MOP analysis performed.
- scale - value according to the argument scale.
- center - value according to the argument center.
- calculate_distance - value according to the argument calculate_distance.
- distance - option regarding distance used.
- percentage - percentage of m used as reference for distance calculation.
- rescale_distance - value according to the argument rescale_distance.
- fix_NA - value according to the argument fix_NA.
- N_m - total number of elements (cells with values or valid rows) in m.
- N_g - total number of elements (cells with values or valid rows) in g.
- m_ranges - the range (minimum and maximum values) of the variable in reference conditions (m)
mop_distances - if calculate_distance = TRUE, a SpatRaster or vector with distance values for the set of interest (g). Higher values represent greater dissimilarity compared to the set of reference (m).
mop_basic - a SpatRaster or vector, for the set of interest, representing conditions in which at least one of the variables is non-analogous to the set of reference. Values should be: 1 for non-analogous conditions, and NA for conditions inside the ranges of the reference set.
mop_simple - a SpatRaster or vector, for the set of interest, representing how many variables in the set of interest are non-analogous to those in the reference set. NA is used for conditions inside the ranges of the reference set.
mop_detailed - a list containing:
- interpretation_combined - a data.frame to help identify combinations of variables in towards_low_combined and towards_high_combined that are non-analogous to m.
- towards_low_end - a SpatRaster or matrix for all variables representing where non-analogous conditions were found towards low values of each variable.
- towards_high_end - a SpatRaster or matrix for all variables representing where non-analogous conditions were found towards high values of each variable.
- towards_low_combined - a SpatRaster or vector with values representing the identity of the variables found to have non-analogous conditions towards low values. If vector, interpretation requires the use of the data.frame interpretation_combined.
- towards_high_combined - a SpatRaster or vector with values representing the identity of the variables found to have non-analogous conditions towards high values. If vector, interpretation requires the use of the data.frame interpretation_combined.

Examples

# Step 1: Organize variables for current projection
## Import current variables (used to fit models)
var <- terra::rast(system.file("extdata", "Current_variables.tif",
                               package = "kuenm2"))

## Create a folder in a temporary directory to copy the variables
out_dir_current <- file.path(tempdir(), "Current_raw4")
dir.create(out_dir_current, recursive = TRUE)

## Save current variables in temporary directory
terra::writeRaster(var, file.path(out_dir_current, "Variables.tif"))


# Step 2: Organize future climate variables (example with WorldClim)
## Directory containing the downloaded future climate variables (example)
in_dir <- system.file("extdata", package = "kuenm2")

## Create a folder in a temporary directory to copy the future variables
out_dir_future <- file.path(tempdir(), "Future_raw4")

## Organize and rename the future climate data (structured by year and GCM)
### 'SoilType' will be appended as a static variable in each scenario
organize_future_worldclim(input_dir = in_dir, output_dir = out_dir_future,
                          name_format = "bio_", static_variables = var$SoilType)

# Step 3: Prepare data to run multiple projections
## An example with maxnet models
## Import example of fitted_models (output of fit_selected())
data(fitted_model_maxnet, package = "kuenm2")

## Prepare projection data using fitted models to check variables
pr <- prepare_projection(models = fitted_model_maxnet,
                         present_dir = out_dir_current,
                         future_dir = out_dir_future,
                         future_period = c("2041-2060", "2081-2100"),
                         future_pscen = c("ssp126", "ssp585"),
                         future_gcm = c("ACCESS-CM2", "MIROC6"),
                         raster_pattern = ".tif*")

# Step 4: Perform MOP for all projection scenarios
## Create a folder to save MOP results
out_dir <- file.path(tempdir(), "MOPresults")
dir.create(out_dir, recursive = TRUE)

## Run MOP
kmop <- projection_mop(data = fitted_model_maxnet, projection_data = pr,
                       out_dir = out_dir, type = "detailed")

kuenm2 documentation built on April 21, 2026, 1:07 a.m.