Manuals/calci/KFUNCTION

KFUNCTION (Number)

• $Number$ is any real number.

Description

• This function shows the value of the K function.
• In $KFUNCTION(Number)$,Number is any real number.
• K function is named as Ripley's K Function.
• It is defined as how the spatial clustering or dispersion of feature centroids changes when the neighborhood size changes.
• When using this tool, specify the number of distances to evaluate and, optionally, a starting distance and/or distance increment.
• The K-Function is given as :

$L(d)={\frac {\sqrt {A\sum _{i=1}^{n}\sum _{j=1,j\neq i}^{n}k(i,j)}}{\pi n(n-1)}}$

Where d is the distance, n is equal to the total number of features. 

• $A$ represents the total area of the features and $k_{i,j}$ is a weight.
• If there is no edge correction, then the weight will be equal to one when the distance between i and j is less than d, and will equate to zero otherwise.

Examples

1. KFUNCTION(5) = 27648
2. KFUNCTION(15) = 1.8473984485535928e+99
3. KFUNCTION(6.453) = 86400000

See Also

• SUM
• SQRT

References

K Function

• List of Main Z Functions

• Z3 home