# compileCDF: Generic Calculation of Cumulative Distribution Function of... In spatstat.explore: Exploratory Data Analysis for the 'spatstat' Family

 compileCDF R Documentation

## Generic Calculation of Cumulative Distribution Function of Distances

### Description

A low-level function which calculates the estimated cumulative distribution function of a distance variable.

### Usage

``````compileCDF(D, B, r, ..., han.denom=NULL, check=TRUE)
``````

### Arguments

 `D` A vector giving the distances from each data point to the target. `B` A vector giving the distances from each data point to the window boundary, or censoring distances. `r` An equally spaced, finely spaced sequence of distance values at which the CDF should be estimated. `...` Ignored. `han.denom` Denominator for the Hanisch-Chiu-Stoyan estimator. A single number, or a numeric vector with the same length as `r`. `check` Logical value specifying whether to check validity of the data, for example, that the vectors `D` and `B` have the same length, and contain non-negative numbers.

### Details

This low-level function calculates estimates of the cumulative distribution function

`F(r) = P(D \le r)`

of a distance variable `D`, given a vector of observed values of `D` and other information. Examples of this concept include the empty space distance function computed by `Fest` and the nearest-neighbour distance distribution function `Gest`.

This function `compileCDF` and its siblings `compileK` and `compilepcf` are useful for code development and for teaching, because they perform a common task, and do the housekeeping required to make an object of class `"fv"` that represents the estimated function. However, they are not very efficient.

The argument `D` should be a numeric vector of shortest distances measured from each ‘query’ point to the ‘target’ set. The argument `B` should be a numeric vector of shortest distances measured from each ‘query’ point to the boundary of the window of observation. All entries of `D` and `B` should be non-negative.

`compileCDF` calculates estimates of the cumulative distribution function `F(r)` using the border method (reduced sample estimator), the Kaplan-Meier estimator and, if `han.denom` is given, the Hanisch-Chiu-Stoyan estimator. See Chapter 8 of Baddeley, Rubak and Turner (2015).

The result is an object of class `"fv"` representing the estimated function. Additional columns (such as a column giving the theoretical value) must be added by the user, with the aid of `bind.fv`.

### Value

An object of class `"fv"` representing the estimated function.

### References

`compileK`.

`bind.fv` to add more columns.

### Examples

``````  ## Equivalent to Gest(japanesepines)
X <- japanesepines
D <- nndist(X)
B <- bdist.points(X)
r <- seq(0, 0.25, by=0.01)
H <- eroded.areas(Window(X), r)
G <- compileCDF(D=D, B=B, r=r, han.denom=H)