Get centroid size

Calculate the centroid size (CS): the square root of the sum of squared distances from each point to the centroid.

Usage

get_centroid_size(x, ..., .cols = NULL)

centsize(x, ..., .cols = NULL)

Arguments

x

A matrix (nx2), list of matrices, or tibble with coo columns.

...

Additional arguments (reserved for future use).

.cols

Column name(s) to process when x is a tibble. If NULL, automatically detects columns containing coo objects.

Value

• If x is a single matrix: returns a numeric scalar

• If x is a list: returns a numeric vector

• If x is a tibble: returns a numeric vector extracted from coo column

Details

Centroid size is a common size measure in geometric morphometrics. It is scale-independent and used for allometric correction.

For tibbles, this function extracts values without modifying the tibble. Use within mutate() to add as a column: mutate(df, cs = get_centroid_size(coo))

Examples

get_centroid_size(shapes$cat)
#> [1] 847.9577
get_centroid_size(shapes)
#> $cat
#> [1] 847.9577
#> 
#> $dog
#> [1] 950.7276
#> 
#> $heart
#> [1] 978.0189
#> 
#> $leaf2
#> [1] 814.8906
#> 

# Extract from tibble
sizes <- get_centroid_size(bot)

# Add to tibble
bot$centsize <- get_centroid_size(bot)