This function performs thinning of spatial points by rounding their coordinates to a specified precision and removing duplicates. It can perform multiple trials of this process and return the results for all or just the best trial.
Usage
precision_thinning(
coordinates,
precision = 4,
trials = 10,
all_trials = FALSE,
priority = NULL
)Arguments
- coordinates
A numeric matrix or data frame with two columns representing the longitude and latitude of points.
- precision
An integer specifying the number of decimal places to which coordinates should be rounded. Default is 4.
- trials
An integer specifying the number of thinning trials to perform. Default is 10.
- all_trials
A logical value indicating whether to return results for all trials (`TRUE`) or just the first/best trial (`FALSE`). Default is `FALSE`.
- priority
A of the same length as the number of points with numerical values indicating the priority of each point. Instead of eliminating points randomly, the points are preferred accoridng to these values.
Value
If `all_trials` is `FALSE`, returns a logical vector indicating which points were kept in the first trial. If `all_trials` is `TRUE`, returns a list of logical vectors, one for each trial.
Details
The function performs multiple trials to account for randomness in the order of point selection. By default, it returns the first trial, but setting `all_trials = TRUE` will return the results of all trials.
Examples
# Example usage
coordinates <- matrix(c(-123.3656, 48.4284, -123.3657, 48.4285, -123.3658, 48.4286), ncol = 2)
result <- precision_thinning(coordinates, precision = 3, trials = 5, all_trials = TRUE)
print(result)
#> [[1]]
#> [1] TRUE TRUE TRUE
#>
#> [[2]]
#> [1] TRUE TRUE TRUE
#>
#> [[3]]
#> [1] TRUE TRUE TRUE
#>
#> [[4]]
#> [1] TRUE TRUE TRUE
#>
#> [[5]]
#> [1] TRUE TRUE TRUE
#>
# Example with a single trial and lower precision
result_single <- precision_thinning(coordinates, precision = 2, trials = 1, all_trials = FALSE)
print(result_single)
#> [[1]]
#> [1] FALSE TRUE TRUE
#>