estimateDistFun {Chicago} | R Documentation

## Estimate the Distance Function

### Description

Estimates the function that models how the expected number of counts decreases with increasing distance.

### Usage

    estimateDistFun(cd, method = "cubic", plot = TRUE, outfile = NULL)

### Arguments

`cd` | A `chicagoData` object.
`method` | Choice of method: "cubic" is currently the only allowed option, which fits a cubic function with linear extrapolation, on a log-log scale.

`plot` | Output a diagnostic plot.
`outfile` | If `NULL`, plot to current device. Otherwise, plot to the .pdf file `outfile`.

### Details

By default, we look in 75 distance bins, and a cubic fit is used. For distances that lie outside of the bin boundaries, it is assumed that the function is log-linear, with continuity of `f` and its first derivative on the log-scale.

### Value

An object of class `chicagoData`, with the parameters of the distance function present as params(cd)$distFunParams.

### Author(s)

Mikhail Spivakov, Jonathan Cairns, Paula Freire Pritchett

### See Also

`chicagoPipeline`, `plotDistFun`

### Examples

    data(cdUnitTest)
    estimateDistFun(cdUnitTest)

[Package Chicago version 1.20.0 Index]