Type:	Package
Title:	Functions for Estimating Centrographic Statistics
Version:	4.1.2
Date:	2024-04-18
Maintainer:	Tarmo K. Remmel <remmelt@yorku.ca>
Description:	A collection of functions for computing centrographic statistics (e.g., standard distance, standard deviation ellipse, standard deviation box) for observations taken at point locations. Separate plotting functions have been developed for each measure. Users interested in writing results to ESRI shapefiles can do so by using results from 'aspace' functions as inputs to the convert.to.shapefile() and write.shapefile() functions in the 'shapefiles' library. We intend to provide 'terra' integration for geographic data in a future release. The 'aspace' package was originally conceived to aid in the analysis of spatial patterns of travel behaviour (see Buliung and Remmel 2008 <doi:10.1007/s10109-008-0063-7>).
License:	GPL-3
Depends:	R (≥ 2.3.0), splancs, Hmisc
LazyData:	true
Packaged:	2024-04-18 01:09:20 UTC; tarmo
Repository:	CRAN
Date/Publication:	2024-04-19 23:52:53 UTC
NeedsCompilation:	no
Author:	Tarmo K. Remmel [aut, cre], Randy Bui [aut], Ron N. Buliung [aut]

A collection of functions for estimating centrographic statistics and computational geometries for spatial point patterns

Description

A collection of functions for computing centrographic statistics (e.g., standard distance, standard deviation ellipse, standard deviation box) for observations taken at point locations. The 'aspace' package was originally conceived to aid in the analysis of spatial patterns of travel behaviour (see Buliung and Remmel, 2008).

Details

Author(s)

Randy Bui, Ron N. Buliung, Tarmo K. Remmel

References

Bachi, R. 1963. Standard distance measures and related methods for spatial analysis. Papers of the Regional Science Association 10: 83-132.

Buliung, R.N. and Remmel, T. (2008) Open source, spatial analysis, and activity travel behaviour research: capabilities of the aspace package. Journal of Geographical Systems, 10: 191-216.

Buliung, R.N. and Kanaroglou, P.S. (2006) Urban form and household activity-travel behaviour. Growth and Change, 37: 174-201.

Ebdon, D. 1988. Statistics in Geography 2nd Edition. Oxford UK: Blackwell.

Levine, N. 2002. CrimeStat II: A Spatial Statistics Program for the Analysis of Crime Incident Locations (version 2.0) Houston TX/National Institute of Justice, Washington DC: Ned Levine & Associates.

Compute inverse cosine with angle given in degrees

Description

Provides the functionality of acos, but for input angles measured in degrees (not radians).

Usage

acos_d(theta = 0)

Arguments

Details

Since the R default is to compute trigonometric functions on angular measurements stored in radians, this simple function performs the conversion from degrees, reducing the need to do so a priori, outside the function.

Value

Returns a numeric value for the inverse cosine of the specified angular measurement

Note

To reduce the need for unit conversions prior to calling trigonometric functions, this function accepts input in angular degrees rather than radians. Depending on the data source, this function may be preferred to the existing version requiring input in angular radians.

Author(s)

Tarmo K. Remmel

See Also

sin_d, cos_d, tan_d, asin_d, atan_d

Examples

acos_d(theta = 90)

Demo Data: x and y coordinates of 10 specified point locations

Description

This is a simple two-column data frame (or matrix) containing x,y coordinates for a series of point locations. These data mimic UTM coordinates such that the first column contains Easting (x), and the second Northing (y) coordinates for the set of unique points.

Usage

data(activities)

Format

A data frame with 10 observations on the following 2 variables.

col1

A numeric vector of x-coordinates

col2

A numeric vector of y-coordinates

Details

The coordinates of the points must have the same units and projection as the specified center.

Source

This demonstration data has been manufactured for illustrative purposes only.

Examples

  data(activities)
  str(activities)
  plot(activities)

Demo Data: x and y coordinates of 10 specified point locations

Description

This is a simple two-column data frame (or matrix) containing x,y coordinates for a series of point locations. These data mimic UTM coordinates such that the first column contains Easting (x), and the second Northing (y) coordinates for the set of unique points.

Usage

data(activities2)

Format

A data frame with 10 observations on the following 2 variables.

col1

A numeric vector of x-coordinates

col2

A numeric vector of y-coordinates

Details

The coordinates of the points must have the same units and projection as the specified center.

Source

This demonstration data has been manufactured for illustrative purposes only.

Examples

  data(activities2)
  str(activities2)
  plot(activities2)

Converts degrees to radians

Description

This function converts an angular measure stored in degrees to radians. This is an alternative to the rad function available in the package circular.

Usage

as_radians(theta = 0)

Arguments

Details

Achieves a very simple conversion with a convenient function call.

Value

Returns a numeric value for an angle in radians that is equivalent to the input theta in degrees.

Note

The purpose of this function is to reduce computer code clutter when using angular measuremnts in R. The simple function call ensures that degree to radian conversions are completed consistently and accurately. Since trigonometric functions in R require angular measures in radians rather than degrees, this simple function can be used for simple angular unit conversion.

Author(s)

Tarmo K. Remmel

See Also

sin_d, cos_d, tan_d, asin_d, acos_d, atan_d

Examples

as_radians(theta = 90)

Compute inverse sine with angle given in degrees

Description

Provides the functionality of asin, but for input angles measured in degrees (not radians).

Usage

asin_d(theta = 0)

Arguments

Details

Since the R default is to compute trigonometric functions on angular measurements stored in radians, this simple function performs the conversion from degrees, reducing the need to do so a priori, outside the function.

Value

Returns a numeric value for the inverse sine of the specified angular measurement.

Note

To reduce the need for unit conversions prior to calling trigonometric functions, this function accepts input in angular degrees rather than radians. Depending on the data source, this function may be preferred to the existing version requiring input in angular radians.

Author(s)

Tarmo K. Remmel

See Also

sin_d, cos_d, tan_d, acos_d, atan_d

Examples

asin_d(theta = 90)

Compute inverse tangent with angle given in degrees

Description

Provides the functionality of atan, but for input angles measured in degrees (not radians).

Usage

atan_d(theta = 0)

Arguments

Details

Since the R default is to compute trigonometric functions on angular measurements stored in radians, this simple function performs the conversion from degrees, reducing the need to do so a priori, outside the function.

Value

Returns a numeric value for the inverse tangent of the specified angular measurement.

Note

To reduce the need for unit conversions prior to calling trigonometric functions, this function accepts input in angular degrees rather than radians. Depending on data, this function may be preferred to the existing version requiring input in angular radians.

Author(s)

Tarmo K. Remmel

See Also

sin_d, cos_d, tan_d, asin_d, acos_d

Examples

atan_d(theta = 90)

Calculate the Standard Deviation Box

Description

The orthogonal dispersion of a set of points can be described using the standard deviation of the x- and y-coordinates of a set of point observations. The orthogonal dispersion can then be visualized with a Standard Deviation Box. This function computes the properties of the Standard Deviation Box (SD Box) from a set of point observations.

Usage

calc_box(id=1, centre.xy=NULL, calccentre=TRUE, weighted=FALSE,
weights=NULL, points=NULL, verbose=FALSE)

Arguments

Details

Use the LOCATIONS element in the output list object along with the ATTRIBUTES elements can be used to produce shapefiles or other vector point files for geographic data.

Value

The returned result is a list:

Note

Results specific for plotting are stored in the FORPLOTTING element within the produced list object. Pass the entire object to plot_box() and the function automatically extracts this information. This function can be used on its own (once) or repetitively in a loop to process grouped point data stored in a larger table. When used repetitively, be sure to increment the id argument to ensure that each SD BOX has a unique identifier.

Author(s)

Tarmo K. Remmel, Randy Bui, Ron N. Buliung

See Also

calc_sdd, calc_sde, calc_cmd, calc_cf, calc_cf2pts, calc_mnc, calc_mdc, wtd.var

Examples

# BOX EXAMPLE
data(activities)
a <- calc_box(id=1, centre.xy=NULL, points=activities)
str(a)
print(a)

# IF THE RESULT OF THIS FUNCTION IS STORED TO AN OBJECT, THE plot_box()
# FUNCTION WILL TAKE THAT OBJECT AS INPUT FOR PLOTTING VIA THE datin ARGUMENT

# BOX TO SHAPEFILE EXAMPLE (REMOVE THE COMMENTS TO RUN)
# shp <- convert.to.shapefile(a$LOCATIONS, a$ATTRIBUTES, "id", 5)
# write.shapefile(shp, "BOX_Shape", arcgis=T)

Central Feature (CF) Calculator

Description

Identifies the central feature within a set of point locations.

Usage

calc_cf(id=1, points=NULL, verbose=FALSE)

Arguments

Details

Use the LOCATIONS element in the output list object along with the ATTRIBUTES elements can be used to produce shapefiles or other vector point files for geographic data.

Value

The returned result is a list:

Note

Results specific for plotting are stored in the FORPLOTTING element within the produced list object. Pass the entire object to plot_box() and the function automatically extracts this information. This function can be used on its own (once) or repetitively in a loop to process grouped point data stored in a larger table. When used repetitively, be sure to increment the id argument to ensure that each CF has a unique identifier.

Author(s)

Randy Bui, Ron Buliung, Tarmo K Remmel

See Also

calc_box, calc_sdd, calc_sde, calc_cmd, calc_cf2pts, calc_mnc, calc_mdc

Examples

# CF EXAMPLE
data(activities)
a <- calc_cf(id=1, points=activities)
str(a)
print(a)

# BOX TO SHAPEFILE EXAMPLE (REMOVE THE COMMENTS TO RUN)
# shp <- convert.to.shapefile(a$LOCATIONS, a$ATTRIBUTES, "id", 5)
# write.shapefile(shp, "CF_Shape", arcgis=T)

Central feature between 2 point patterns (CF2PTS) Calculator

Description

Central feature of point2 within point1. Identifies the central feature as the point location in the first pattern that has the smallest cummulative distance to features in a second point pattern.

Usage

calc_cf2pts(id=1, points1=NULL, points2=NULL, verbose=FALSE)

Arguments

Details

Use the LOCATIONS element in the output list object along with the ATTRIBUTES elements can be used to produce shapefiles or other vector point files for geographic data.

Value

The returned result is a list:

Note

Results specific for plotting are stored in the FORPLOTTING element within the produced list object. This function can be used on its own (once) or repetitively in a loop to process grouped point data stored in a larger table. When used repetitively, be sure to increment the id argument to ensure that each CF2PTS has a unique identifier.

Author(s)

Randy Bui, Ron Buliung

See Also

calc_box, calc_sdd, calc_sde, calc_cmd, calc_cf, calc_mnc, calc_mdc

Examples

# CF2PTS EXAMPLE
data(activities)
data(activities2)
a <- calc_cf2pts(id=1, points1=activities, points2=activities2)
str(a)
print(a)

# IF THE RESULT OF THIS FUNCTION IS STORED TO AN OBJECT, THE plot_box()
# FUNCTION WILL TAKE THAT OBJECT AS INPUT FOR PLOTTING VIA THE datin ARGUMENT

# CF2PTS TO SHAPEFILE EXAMPLE (REMOVE THE COMMENTS TO RUN)
# shp <- convert.to.shapefile(a$LOCATIONS, a$ATTRIBUTES, "id", 5)
# write.shapefile(shp, "CF2PTS_Shape", arcgis=T)

Centre of Minimum Distance (CMD) Calculator

Description

Compute the CMD within a set of point locations.

Usage

calc_cmd(id=1, dist=100, points=NULL, verbose=FALSE)

Arguments

Details

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

Value

The returned result is a list:

Note

Results specific for plotting are stored in the FORPLOTTING element within the produced list object. Pass the entire object to plot_box() and the function automatically extracts this information. This function can be used on its own (once) or repetitively in a loop to process grouped point data stored in a larger table. When used repetitively, be sure to increment the id argument to ensure that each SD BOX has a unique identifier.

Author(s)

Randy Bui, Ron Buliung, Tarmo K. Remmel

See Also

calc_box, calc_sdd, calc_sde, calc_cf, calc_cf2pts, calc_mnc, calc_mdc

Examples

# CMD EXAMPLE
a <- calc_cmd(id=1, dist=100, points=activities)
str(a)
print(a)

# CMD TO SHAPEFILE EXAMPLE (REMOVE THE COMMENTS TO RUN)
# shp <- convert.to.shapefile(a$LOCATIONS, a$ATTRIBUTES, "id", 5)
# write.shapefile(shp, "CMD_Shape", arcgis=T)

Median Centre Calculator

Description

Compute the median centre from a series of point locations.

Usage

calc_mdc(id=1, points=NULL, verbose=FALSE)

Arguments

Details

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

Value

The returned result is a list:

Note

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

Author(s)

Randy Bui, Ron Buliung

See Also

calc_box, calc_sdd, calc_sde, calc_cmd, calc_cf, calc_cf2pts, calc_mnc

Examples

# MEDIAN CENTRE EXAMPLE
a <- calc_mdc(id=1, points=activities)
str(a)
print(a)

# MEDIAN CENTRE TO SHAPEFILE EXAMPLE (REMOVE THE COMMENTS TO RUN)
# shp <- convert.to.shapefile(a$LOCATIONS, a$ATTRIBUTES, "id", 5)
# write.shapefile(shp, "Median_Shape", arcgis=T)

Mean Centre Calculator

Description

Compute the mean centre from a series of point locations.

Usage

calc_mnc(id=1, weighted=FALSE, weights=NULL,
 points=NULL, verbose=FALSE)

Arguments

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 returned result is a list:

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

calc_box, calc_sdd, calc_sde, calc_cmd, calc_cf, calc_cf2pts, calc_mdc

Examples

# MEAN CENTRE EXAMPLE
a <- calc_mnc(id=1, points=activities)
str(a)
print(a)

# MEAN CENTRE TO SHAPEFILE EXAMPLE (REMOVE THE COMMENTS TO RUN)
# shp <- convert.to.shapefile(a$LOCATIONS, a$ATTRIBUTES, "id", 5)
# write.shapefile(shp, "Mean_Shape", arcgis=T)

Calculate the Standard Distance Deviation (Standard Distance)

Description

This function computes the Standard Distance Deviation (SDD) or Standard Distance from a set of points.

Usage

calc_sdd(id=1, centre.xy=NULL, calccentre=TRUE, weighted=FALSE,
 weights=NULL, points=NULL, verbose=FALSE)

Arguments

Details

Use the LOCATIONS element in the output list object along with the ATTRIBUTES elements can be used to produce shapefiles or other vector point files for geographic data.

Value

The returned result is a list:

Note

Results specific for plotting are stored in the FORPLOTTING element within the produced list object. Pass the entire object to plot_sdd() and the function automatically extracts this information. This function can be used on its own (once) or repetitively in a loop to process grouped point data stored in a larger table. When used repetitively, be sure to increment the id argument to ensure that each SDD has a unique identifier.

Author(s)

Tarmo K. Remmel, Randy Bui, Ron Buliung

See Also

calc_box, calc_sde, calc_cmd, calc_cf, calc_cf2pts, calc_mnc, calc_mdc

Examples

# SDD EXAMPLE
data(activities)
a <- calc_sdd(id=1, centre.xy=NULL, calccentre=TRUE, points=activities)
str(a)
print(a)

# IF THE RESULT OF THIS FUNCTION IS STORED TO AN OBJECT, THE plot_box()
# FUNCTION WILL TAKE THAT OBJECT AS INPUT FOR PLOTTING VIA THE datin ARGUMENT

# SDD TO SHAPEFILE EXAMPLE (REMOVE THE COMMENTS TO RUN)
# shp <- convert.to.shapefile(a$LOCATIONS, a$ATTRIBUTES,"id",5)
# write.shapefile(shp, "SDD_Shape", arcgis=T)

Calculate the Standard Deviation Ellipse

Description

This function computes the Standard Deviation Ellipse (SDE) from a set of points. The SDE is a centrographic measure used to characterize the dispersion of point observations along two orthogonal axes. The SDE also captures directional bias in a spatial point pattern, the ellipse will be oriented in the direction of maximum dispersion.

Usage

calc_sde(id=1, centre.xy=NULL, calccentre=TRUE,
weighted=FALSE, weights=NULL, points=NULL, verbose=FALSE)

Arguments

Details

Use the LOCATIONS element in the output list object along with the ATTRIBUTES elements can be used to produce shapefiles or other vector point files for geographic data.

Value

The returned result is a list:

Note

Results specific for plotting are stored in the FORPLOTTING element within the produced list object. Pass the entire object to plot_box() and the function automatically extracts this information. This function can be used on its own (once) or repetitively in a loop to process grouped point data stored in a larger table. When used repetitively, be sure to increment the id argument to ensure that each SDE has a unique identifier.

Author(s)

Tarmo K. Remmel, Randy Bui, Ron N. Buliung

References

See chapter 4 of the documentation manual for CrimeStat at http://www.icpsr.umich.edu/CRIMESTAT/ and Ebdon, D. 1987. Statistics in geography. 2nd edition. New York, NY Basil Blackwell Ltd. 232 p.

See Also

calc_box, calc_sde, calc_cmd, calc_cf, calc_cf2pts, calc_mnc, calc_mdc, gridpts

Examples

# SDE EXAMPLE
data(activities)
a <- calc_sde(id=1, centre.xy=NULL, points=activities)
str(a)
print(a)

# IF THE RESULT OF THIS FUNCTION IS STORED TO AN OBJECT, THE plot_sde()
# FUNCTION WILL TAKE THAT OBJECT AS INPUT FOR PLOTTING VIA THE datin ARGUMENT

# SDE TO SHAPEFILE EXAMPLE (REMOVE THE COMMENTS TO RUN)
# shp <- convert.to.shapefile(a$LOCATIONS, a$ATTRIBUTES, "id", 5)
# write.shapefile(shp, "SDE_Shape", arcgis=T)

Demo Data: Coordinates of a single source, centre, location

Description

This is a simple two-element vector containing x,y coordinates for a source or central location associated with a spatial point pattern. In this example, the center location represents a point of importance in an individuals daily activity pattern. Surrounding point locations are places physically contacted by an individual during a particular time interval. Demonstration data mimics UTM coordinates such that the first element represents Easting (x), and the second, Northing (y).

Usage

data(centre)

Format

The format is a two-element vector of numeric entries.

Details

The coordinates of the center must have the same units and projection as the remaining point observations.

Source

This demonstration data has been manufactured for illustrative purposes only.

Examples

  data(centre)
  str(centre)
  plot(centre)
  
## plot_centres by default takes as input the result produced from mean_centre,
## median centre, CF, CF2PTS, and CMD, read from the current workspace.

Compute cosine with angle given in degrees

Description

Provides the functionality of cos, but for input angles measured in degrees (not radians).

Usage

cos_d(theta = 0)

Arguments

Details

Since the R default is to compute trigonometric functions on angular measurements stored in radians, this simple function performs the conversion from degrees, reducing the need to do so a priori, outside the function.

Value

Returns a numeric value for the cosine of the specified angular measurement

Note

To reduce the need for unit conversions prior to calling trigonometric functions, this function accepts input in angular degrees rather than radians. Depending on data, this function may be preferred to the existing version requiring input in angular radians.

Author(s)

Tarmo K. Remmel

See Also

sin_d, tan_d, asin_d, acos_d, atan_d

Examples

cos_d(theta = 90)

Multiple Euclidean distance calculator

Description

Compute distances from a source location (point) to a series of destination locations (points).

Usage

distances(centre.xy = NULL, destmat = NULL, verbose = FALSE)

Arguments

Details

Distance computations are strictly Euclidean between the source point and each destination point.

Value

A vector of distances, where each element corresponds to one of the distance between the source point and a destination (one row) from the destinations matrix.

Note

The order of distances in the output vector corresponds to the order of destination points in the destinations object starting at row = 1 through row = n.

Author(s)

Tarmo K. Remmel

Examples

  data(centre)
  data(activities)
  distances(centre.xy=centre, destmat=activities, verbose=FALSE)  

Plot the Standard Distance Box

Description

This function plots the standard deviation of x- and y-coordinates as a box, with the edges set, respectively, to the standard deviation of the x- and y-coordinates.

Usage

plot_box(datin=NULL, plotnew=TRUE, plothv=FALSE, plotweightedpts=FALSE,
weightedpts.col='black', weightedpts.pch=19, plotpoints=TRUE, 
points.col='black', points.pch=1, plotcentre=TRUE, centre.col='black', 
centre.pch=19, titletxt="Title", xaxis="Easting (m)", 
yaxis="Northing (m)", box.col='black', box.lwd=2, jpeg=FALSE, ...)

Arguments

Details

The element FORPLOTTING contained within the calc_box() output object is required to plot an SD Box. Provide the whole plot_box() output object as the argment for datin.

Value

This function returns a plot in the graphics device.

Author(s)

Tarmo K. Remmel, Randy Bui, Ron N. Buliung

See Also

plot_sdd, plot_sde

Examples

# NEED TO RUN THE BOX GENERATOR FIRST AND PASS THAT TO THE NEXT LINE
a <- calc_box(id=1, points=activities)
plot_box(datin=a, plotnew=TRUE, plothv=FALSE, plotweightedpts=FALSE,
plotpoints=TRUE, plotcentre=TRUE, titletxt="Title", 
xaxis="Easting (m)", yaxis="Northing (m)")

# plot_box() BY DEFAULT, TAKES AS INPUT THE RESULT PRODUCED BY calc_box()

Plot centres

Description

This function plots various centre of a set of point observations.

Usage

plot_centres(datin=NULL, plotnew=FALSE, plotSDE=FALSE,
xaxis="Easting (m)", yaxis="Northing (m)", plotweightedpts=FALSE,
weightedpts.col='black', weightedpts.pch=19, plotpoints=TRUE,
points.col='black', points.pch=1, plotcentre=FALSE, centre.col='black',
centre.pch=19, plotcentral=FALSE, central.col='green', central.pch=19, 
plotCF2PTS=FALSE, CF2PTS.col='orange', CF2PTS.pch=19, plotmedian=FALSE, 
median.col='blue', median.pch=17, plotCMD=FALSE, CMD.col='red',
CMD.pch=17, TITLE="Title", ...)

Arguments

Details

The element FORPLOTTING contained within any of the calc function output lists is required as an argument for datin.

Value

This function returns a plot in the graphics device.

Author(s)

Tarmo K. Remmel, Randy Bui, Ron N. Buliung

See Also

plot_box, plot_sdd, plot_sde

Examples

# MNC (BLACK CIRCLE)
a <- calc_mnc(points=activities)

# MDC (BLUE TRIANGLE)
b <- calc_mdc(points=activities)

# CF (GREEN CIRCLE)
d <- calc_cf(points=activities)

# CMD (RED TRIANGLE)
e <- calc_cmd(points=activities)

# CF2PTS (ORANGE CIRCLE)
f <- calc_cf2pts(points1=activities, points2=activities2)

# BUILD LIST OF OBJECTS TO PASS AS THE datin ARGUMENT
robjects <- list(a,b,d,e,f)
# CALL THE PLOT FUNCTION
plot_centres(datin=robjects, plotnew=TRUE, plotcentre=TRUE, plotmedian=TRUE)

# A FULL CALL COULD LOOK LIKE THE FOLLOWING
plot_centres(datin=robjects, plotnew=TRUE, plotcentre=TRUE,
plotmedian=TRUE, plotcentral=TRUE, plotCMD=TRUE, plotCF2PTS=TRUE)

Plot the Standard Distance Deviation (Standard Distance)

Description

This function plots the SDD as a circle with radius (standard distance), centred on a mean/weighted-mean/user-defined centre of a set of point observations.

Usage

plot_sdd(datin=NULL, plotnew=TRUE, plothv=FALSE, plotweightedpts=FALSE,
weightedpts.col='black', weightedpts.pch=19, plotpoints=TRUE, 
points.col='black', points.pch=1, plotcentre=TRUE, centre.col='black', 
centre.pch=19, titletxt="Title", xaxis="Easting (m)", 
yaxis="Northing (m)", sdd.col='black', sdd.lwd=2, jpeg=FALSE, ...)

Arguments

Details

The element FORPLOTTING contained within the calc_box() output object is required to plot an SD Box. Provide the whole plot_box() output object as the argment for datin.

Value

This function returns a plot in the graphics device.

Author(s)

Tarmo K. Remmel, Randy Bui, Ron N. Buliung

See Also

plot_sde, plot_box

Examples

a <- calc_sdd(points=activities)
plot_sdd(datin=a, plotnew=TRUE, plothv=FALSE, plotweightedpts=FALSE,
plotpoints=TRUE, plotcentre=TRUE, titletxt="Title", 
xaxis="Easting (m)", yaxis="Northing (m)")

# plot_sdd() BY DEFAULT, TAKES AS INPUT THE RESULT PRODUCED BY calc_sdd()

Plot the Standard Deviation Ellipse

Description

This function plots the SDE as an ellipse centred on the mean/weighted/user-defined centre of a set of point observations. The plot characterizes the dispersion of point observations along two orthogonal axes.

Usage

plot_sde(datin=NULL, plotnew=TRUE, plotSDEaxes=FALSE, plotweightedpts=FALSE,
weightedpts.col='black', weightedpts.pch=19, plotpoints=TRUE, 
points.col='black', points.pch=1, plotcentre=TRUE, centre.col='black', 
centre.pch=19, titletxt="Title", xaxis="Easting (m)", 
yaxis="Northing (m)", sde.col='black', sde.lwd=2, jpeg=FALSE, ...)

Arguments

Details

The element FORPLOTTING contained within the calc_box() output object is required to plot an SD Box. Provide the whole plot_box() output object as the argment for datin.

Value

This function returns a plot in the graphics device.

Author(s)

Tarmo K. Remmel, Randy Bui, Ron N. Buliung

See Also

plot_sdd, plot_box

Examples

a <- calc_sde(points=activities)
plot_sde(datin=a, plotnew=TRUE, plotSDEaxes=FALSE, plotweightedpts=FALSE,
plotpoints=TRUE, plotcentre=TRUE, titletxt="Title", 
xaxis="Easting (m)", yaxis="Northing (m)")

# plot_sde() BY DEFAULT, TAKES AS INPUT THE RESULT PRODUCED BY calc_sde()

Compute sine with angle given in degrees

Description

Provides the functionality of sin, but for input angles measured in degrees (not radians).

Usage

sin_d(theta = 0)

Arguments

Details

Since the R default is to compute trigonometric functions on angular measurements stored in radians, this simple function performs the conversion from degrees, reducing the need to do so a priori, outside the function.

Value

Returns a numeric value for the sine of the specified angular measurement

Note

To reduce the need for unit conversions prior to calling trigonometric functions, this function accepts input in angular degrees rather than radians. Depending on data, this function may be preferred to the existing version requiring input in angular radians.

Author(s)

Tarmo K. Remmel

See Also

cos_d, tan_d, asin_d, acos_d, atan_d

Examples

sin_d(theta = 90)

Compute tangent with angle given in degrees

Description

Provides the functionality of tan, but for input angles measured in degrees (not radians).

Usage

tan_d(theta = 0)

Arguments

Details

Since the R default is to compute trigonometric functions on angular measurements stored in radians, this simple function performs the conversion from degrees, reducing the need to do so a priori, outside the function.

Value

Returns a numeric value for the tangent of the specified angular measurement

Note

To reduce the need for unit conversions prior to calling trigonometric functions, this function accepts input in angular degrees rather than radians. Depending on data, this function may be preferred to the existing version requiring input in angular radians.

Author(s)

Tarmo K. Remmel

See Also

sin_d, cos_d, asin_d, acos_d, atan_d

Examples

tan_d(theta = 45)

Weights vector

Description

This is a single column vector for weighting the importance of point locations.

Usage

data(wts)

Format

A single column vector of numeric values.

Details

The weights can be specified according to any reasonable criteria specified by the user

Source

This demonstration data has been manufactured for illustrative purposes only.

Examples

  data(wts)
  str(wts)
  plot(wts)