mean_centre: Mean Centre Calculator

Description Usage Arguments Details Value Note Author(s) See Also Examples

Description

Compute the mean centre from a series of point locations.

Usage

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mean_centre(id=1, filename="mean_centre_Output.txt", 
weighted=FALSE, weights=NULL, points=activities)

Arguments

id

A unique integer to identify the mean centre

filename

A string indicating the ASCII textfile where centre coordinates will be written

weighted

Boolean: Set to TRUE if the weighted mean center is to be computed with weighted coordinates

weights

Weights applied to point observations, number of weights should equal the number of observations

points

A 2-column matrix or data frame containing the set of point observations

Details

Use the meanloc (coordinates) and meanatt(attributes) to produce shapefiles using the convert.to.shapefile and write.shapefile from the shapefiles library

Value

The result is a list of terms:

id

Identifier for the mean centre - it should be unique

weighted

Boolean: TRUE if the weighted mean centre is to be used instead

weights

Weights applied to point observations

CENTRE.x

X-coordinate of the mean centre

CENTRE.y

Y-coordinate of the mean centre

Note

Results are stored in the r.mean object and can be passed through plotting functions. This function can also be used repetitively within a loop to compute multiple mean centres from different datasets.

Author(s)

Randy Bui, Ron Buliung

See Also

median_centre, CMD, CF

Examples

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## Mean centre example
mean_centre(id=1, filename="mean_centre_Output.txt", 
weighted=FALSE, weights=NULL, points=activities)

## Mean centre to shapefile example (exclude the comments below to run script)
## shp <- convert.to.shapefile(meanloc,meanatt,"id",5)
## write.shapefile(shp, "Mean_Shape", arcgis=T)

Example output

Loading required package: splancs
Loading required package: sp

Spatial Point Pattern Analysis Code in S-Plus
 
 Version 2 - Spatial and Space-Time analysis

Loading required package: Hmisc
Loading required package: lattice
Loading required package: survival
Loading required package: Formula
Loading required package: ggplot2

Attaching package: 'Hmisc'

The following object is masked from 'package:splancs':

    zoom

The following objects are masked from 'package:base':

    format.pval, units

Loading required package: shapefiles
Loading required package: foreign

Attaching package: 'shapefiles'

The following objects are masked from 'package:foreign':

    read.dbf, write.dbf

  id CENTRE.x CENTRE.y
1  1 610941.3  4830837

aspace documentation built on May 2, 2019, 6:24 a.m.

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