, Randy Bui [aut], Ron
N. Buliung [aut]| Title: | Functions for Estimating Centrographic Statistics |
|---|---|
| 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>). |
| Authors: | Tarmo K. Remmel [aut, cre]
, Randy Bui [aut], Ron
N. Buliung [aut] |
| Maintainer: | Tarmo K. Remmel <[email protected]> |
| License: | GPL-3 |
| Version: | 4.1.2 |
| Built: | 2024-12-16 06:56:36 UTC |
| Source: | CRAN |
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).
| Package: | aspace |
| Type: | Package |
| Version: | 4.1.0 |
| Date: | 2023-09-05 |
| License: | GPL-3 |
Randy Bui, Ron N. Buliung, Tarmo K. Remmel
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.
Provides the functionality of acos, but for input angles measured in degrees (not radians).
acos_d(theta = 0)acos_d(theta = 0)
theta |
A numeric angular measurement in degrees from north. |
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.
Returns a numeric value for the inverse cosine of the specified angular measurement
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.
Tarmo K. Remmel
sin_d, cos_d,
tan_d, asin_d,
atan_d
acos_d(theta = 90)acos_d(theta = 90)
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.
data(activities)data(activities)
A data frame with 10 observations on the following 2 variables.
col1A numeric vector of x-coordinates
col2A numeric vector of y-coordinates
The coordinates of the points must have the same units and projection as the specified center.
This demonstration data has been manufactured for illustrative purposes only.
data(activities) str(activities) plot(activities)data(activities) str(activities) plot(activities)
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.
data(activities2)data(activities2)
A data frame with 10 observations on the following 2 variables.
col1A numeric vector of x-coordinates
col2A numeric vector of y-coordinates
The coordinates of the points must have the same units and projection as the specified center.
This demonstration data has been manufactured for illustrative purposes only.
data(activities2) str(activities2) plot(activities2)data(activities2) str(activities2) plot(activities2)
This function converts an angular measure stored in degrees to radians. This is an alternative to the rad function available in the package circular.
as_radians(theta = 0)as_radians(theta = 0)
theta |
A numeric angular measurement in degrees from north. |
Achieves a very simple conversion with a convenient function call.
Returns a numeric value for an angle in radians that is equivalent to the input theta in degrees.
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.
Tarmo K. Remmel
sin_d, cos_d, tan_d,
asin_d, acos_d, atan_d
as_radians(theta = 90)as_radians(theta = 90)
Provides the functionality of asin, but for input angles measured in degrees (not radians).
asin_d(theta = 0)asin_d(theta = 0)
theta |
A numeric angular measurement in degrees from north. |
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.
Returns a numeric value for the inverse sine of the specified angular measurement.
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.
Tarmo K. Remmel
sin_d, cos_d,
tan_d, acos_d,
atan_d
asin_d(theta = 90)asin_d(theta = 90)
Provides the functionality of atan, but for input angles measured in degrees (not radians).
atan_d(theta = 0)atan_d(theta = 0)
theta |
A numeric angular measurement in degrees from north. |
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.
Returns a numeric value for the inverse tangent of the specified angular measurement.
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.
Tarmo K. Remmel
sin_d, cos_d,
tan_d, asin_d,
acos_d
atan_d(theta = 90)atan_d(theta = 90)
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.
calc_box(id=1, centre.xy=NULL, calccentre=TRUE, weighted=FALSE, weights=NULL, points=NULL, verbose=FALSE)calc_box(id=1, centre.xy=NULL, calccentre=TRUE, weighted=FALSE, weights=NULL, points=NULL, verbose=FALSE)
id |
A unique integer to identify a SD Box |
centre.xy |
A vector of length 2, containing the x- and y-coordinates of the geographic centre of the SD Box |
calccentre |
Boolean: Set to TRUE if the mean center is to be calculated |
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 input to the calc_box function |
verbose |
Boolean: Set to TRUE if extensive feedback is desired on the standard output |
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.
The returned result is a list:
TYPE |
The type of calculation results stored in the object: BOX, SDD, SDE, CMD, CF, or CF2PTS, MNC, MDC |
DATE |
The date and time that the function was run |
ID |
Identifier for the SD Box shape - it should be unique |
LOCATIONS |
Locations pertinent for the BOX that can be used with ATTRIBUTES if wishing to build a vector point file for geographic data outside of this pacakge. |
FORPLOTTING |
Coordinates and identifiers used for plotting by plot_box() |
ATTRIBUTES |
Attributes for the output BOX that can be used with LOCATIONS coordinates if wishing to build a vector point file for geographic data outside of this package. |
id |
Identifier for the SD Box shape - it should be unique |
calccentre |
Boolean: TRUE if the mean centre was estimated |
weighted |
Boolean: TRUE if the weighted mean centre was estimated |
CENTRE.x |
X-coordinate of the centre |
CENTRE.y |
Y-coordinate of the centre |
SD.x |
Orthogonal standard deviation in the x-axis |
SD.y |
Orthogonal standard deviation in the y-axis |
Box.area |
Area of the standard deviation box |
NW.coord |
North-west coordinates of SD Box |
NE.coord |
North-east coordinates of SD Box |
SW.coord |
South-west coordinates of SD Box |
SE.coord |
South-east coordinates of SD Box |
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.
Tarmo K. Remmel, Randy Bui, Ron N. Buliung
calc_sdd,
calc_sde,
calc_cmd,
calc_cf,
calc_cf2pts,
calc_mnc,
calc_mdc,
wtd.var
# 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)# 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)
Identifies the central feature within a set of point locations.
calc_cf(id=1, points=NULL, verbose=FALSE)calc_cf(id=1, points=NULL, verbose=FALSE)
id |
A unique integer to identify the CF |
points |
A 2-column matrix or data frame containing the set of point observations |
verbose |
Boolean flag for verbose output to monitor |
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.
The returned result is a list:
TYPE |
The type of calculation results stored in the object: BOX, SDD, SDE, CMD, CF, or CF2PTS, MNC, MDC |
DATE |
The date and time that the function was run |
ID |
Identifier for the central feature - it should be unique |
LOCATIONS |
Locations pertinent for the CF that can be used with ATTRIBUTES if wishing to build a vector point file for geographic data outside of this pacakge. |
FORPLOTTING |
Coordinates and identifiers used for plotting. |
ATTRIBUTES |
Attributes for the output CF that can be used with LOCATIONS coordinates if wishing to build a vector point file for geographic data outside of this package. |
id |
Identifier for the central feature - it should be unique |
CF.x |
X-coordinate of the central feature |
CF.y |
Y-coordinate of the central feature |
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.
Randy Bui, Ron Buliung, Tarmo K Remmel
calc_box,
calc_sdd,
calc_sde,
calc_cmd,
calc_cf2pts,
calc_mnc,
calc_mdc
# 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)# 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 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.
calc_cf2pts(id=1, points1=NULL, points2=NULL, verbose=FALSE)calc_cf2pts(id=1, points1=NULL, points2=NULL, verbose=FALSE)
id |
A unique integer to identify the CF2PTS |
points1 |
A 2-column matrix or data frame containing the first set of point observations |
points2 |
A 2-column matrix or data frame containing the second set of point observations |
verbose |
A Boolean flag to control verbose reporting on monitor |
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.
The returned result is a list:
TYPE |
The type of calculation results stored in the object: BOX, SDD, SDE, CMD, CF, or CF2PTS, MNC, MDC |
DATE |
The date and time that the function was run |
ID |
Identifier for the central feature - it should be unique |
LOCATIONS |
Locations pertinent for the CF2PTS that can be used with ATTRIBUTES if wishing to build a vector point file for geographic data outside of this pacakge. |
FORPLOTTING |
Coordinates and identifiers used for plotting. |
ATTRIBUTES |
Attributes for the output CF2PTS that can be used with LOCATIONS coordinates if wishing to build a vector point file for geographic data outside of this package. |
id |
Identifier for the central feature - it should be unique |
CF2PTS.x |
X-coordinate of the central feature |
CF2PTS.y |
Y-coordinate of the central feature |
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.
Randy Bui, Ron Buliung
calc_box,
calc_sdd,
calc_sde,
calc_cmd,
calc_cf,
calc_mnc,
calc_mdc
# 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)# 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)
Compute the CMD within a set of point locations.
calc_cmd(id=1, dist=100, points=NULL, verbose=FALSE)calc_cmd(id=1, dist=100, points=NULL, verbose=FALSE)
id |
A unique integer to identify the CMD |
dist |
Hold distance value between i and ith iterations |
points |
A 2-column matrix or data frame containing the set of point observations |
verbose |
A Boolean flag to control verbose feedback on screen |
Use the cmdloc (coordinates) and cmdatt(attributes) to produce shapefiles using the convert.to.shapefile and write.shapefile from the shapefiles library
The returned result is a list:
TYPE |
The type of calculation results stored in the object: BOX, SDD, SDE, CMD, CF, or CF2PTS, MNC, MDC |
DATE |
The date and time that the function was run |
ID |
Identifier for the CMD - it should be unique |
LOCATIONS |
Locations pertinent for the CMD that can be used with ATTRIBUTES if wishing to build a vector point file for geographic data outside of this pacakge. |
FORPLOTTING |
Coordinates and identifiers used for plotting by plot_cmd() |
ATTRIBUTES |
Attributes for the output CMD that can be used with LOCATIONS coordinates if wishing to build a vector point file for geographic data outside of this package. |
id |
Identifier for the CMD - it should be unique |
CMD.x |
X-coordinate of the CMD |
CMD.y |
Y-coordinate of the CMD |
distance |
Hold distance value between i and ith iterations (metres |
Number of Cells |
Hold number of cells in each grid created for each iteration |
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.
Randy Bui, Ron Buliung, Tarmo K. Remmel
calc_box,
calc_sdd,
calc_sde,
calc_cf,
calc_cf2pts,
calc_mnc,
calc_mdc
# 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)# 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)
Compute the median centre from a series of point locations.
calc_mdc(id=1, points=NULL, verbose=FALSE)calc_mdc(id=1, points=NULL, verbose=FALSE)
id |
A unique integer to identify the median centre |
points |
A 2-column matrix or data frame containing the set of point observations |
verbose |
A Boolean flag to control verbose content on the monitor |
Use the medianloc (coordinates) and medianatt(attributes) to produce shapefiles using the convert.to.shapefile and write.shapefile from the shapefiles library
The returned result is a list:
TYPE |
The type of calculation results stored in the object: BOX, SDD, SDE, CMD, CF, or CF2PTS, MNC, MDC |
DATE |
The date and time that the function was run |
ID |
Identifier for the median centre - it should be unique |
LOCATIONS |
Locations pertinent for the MDC that can be used with ATTRIBUTES if wishing to build a vector point file for geographic data outside of this pacakge. |
FORPLOTTING |
Coordinates and identifiers used for plotting. |
ATTRIBUTES |
Attributes for the output MDC that can be used with LOCATIONS coordinates if wishing to build a vector point file for geographic data outside of this package. |
id |
Identifier for the median centre - it should be unique |
median.x |
X-coordinate of the median centre |
median.y |
Y-coordinate of the median centre |
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.
Randy Bui, Ron Buliung
calc_box,
calc_sdd,
calc_sde,
calc_cmd,
calc_cf,
calc_cf2pts,
calc_mnc
# 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)# 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)
Compute the mean centre from a series of point locations.
calc_mnc(id=1, weighted=FALSE, weights=NULL, points=NULL, verbose=FALSE)calc_mnc(id=1, weighted=FALSE, weights=NULL, points=NULL, verbose=FALSE)
id |
A unique integer to identify the mean centre |
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 |
verbose |
A Boolean flag that controls verbose feedback to the monitor |
Use the meanloc (coordinates) and meanatt(attributes) to produce shapefiles using the convert.to.shapefile and write.shapefile from the shapefiles library
The returned result is a list:
TYPE |
The type of calculation results stored in the object: BOX, SDD, SDE, CMD, CF, or CF2PTS, MNC, MDC |
DATE |
The date and time that the function was run |
ID |
Identifier for the mean centre - it should be unique |
LOCATIONS |
Locations pertinent for the MNC that can be used with ATTRIBUTES if wishing to build a vector point file for geographic data outside of this pacakge. |
FORPLOTTING |
Coordinates and identifiers used for plotting. |
ATTRIBUTES |
Attributes for the output MNC that can be used with LOCATIONS coordinates if wishing to build a vector point file for geographic data outside of this package. |
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 |
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.
Randy Bui, Ron Buliung
calc_box,
calc_sdd,
calc_sde,
calc_cmd,
calc_cf,
calc_cf2pts,
calc_mdc
# 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)# 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)
This function computes the Standard Distance Deviation (SDD) or Standard Distance from a set of points.
calc_sdd(id=1, centre.xy=NULL, calccentre=TRUE, weighted=FALSE, weights=NULL, points=NULL, verbose=FALSE)calc_sdd(id=1, centre.xy=NULL, calccentre=TRUE, weighted=FALSE, weights=NULL, points=NULL, verbose=FALSE)
id |
A unique integer to identify a SDD estimate |
centre.xy |
A vector of length 2, containing the x- and y-coordinates of the SDD centre |
calccentre |
Boolean: Set to TRUE if the mean center is to be calculated |
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 input to the calc_sdd function |
verbose |
Boolean: Set to TRUE if extensive feedback is desired on the standard output |
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.
The returned result is a list:
TYPE |
The type of calculation results stored in the object: BOX, SDD, SDE, CMD, CF, or CF2PTS, MNC, MDC |
DATE |
The date and time that the function was run |
ID |
Identifier for the SDD shape - it should be unique |
LOCATIONS |
Locations pertinent for the SDD that can be used with ATTRIBUTES if wishing to build a vector point file for geographic data outside of this pacakge. |
FORPLOTTING |
Coordinates and identifiers used for plotting by plot_sdd() |
ATTRIBUTES |
Attributes for the output SDD that can be used with LOCATIONS coordinates if wishing to build a vector point file for geographic data outside of this package. |
id |
Identifier for the SDD shape - it should be unique |
calccentre |
Boolean: TRUE if mean centre is computed |
weighted |
Boolean: TRUE if the weighted mean centre is to be used instead |
CENTRE.x |
X-coordinate of the centre |
CENTRE.y |
Y-coordinate of the centre |
SDD.radius |
SDD value, radius of the SDD |
SDD.area |
Area of the SDD circle |
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.
Tarmo K. Remmel, Randy Bui, Ron Buliung
calc_box,
calc_sde,
calc_cmd,
calc_cf,
calc_cf2pts,
calc_mnc,
calc_mdc
# 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)# 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)
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.
calc_sde(id=1, centre.xy=NULL, calccentre=TRUE, weighted=FALSE, weights=NULL, points=NULL, verbose=FALSE)calc_sde(id=1, centre.xy=NULL, calccentre=TRUE, weighted=FALSE, weights=NULL, points=NULL, verbose=FALSE)
id |
A unique integer to identify the shape |
centre.xy |
A vector of length 2, containing the x- and y-coordinates of the SDE centre (Planar Coordinates Only!) |
calccentre |
Boolean: Set to TRUE if the mean center is to be calculated |
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 point coordinates |
verbose |
Boolean: Set to TRUE if extensive feedback is desired on the standard output |
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.
The returned result is a list:
TYPE |
The type of calculation results stored in the object: BOX, SDD, SDE, CMD, CF, or CF2PTS, MNC, MDC |
DATE |
The date and time that the function was run |
ID |
Identifier for the SDE shape - it should be unique |
LOCATIONS |
Locations pertinent for the SDE that can be used with ATTRIBUTES if wishing to build a vector point file for geographic data outside of this pacakge. |
FORPLOTTING |
Coordinates and identifiers used for plotting by plot_sde() |
ATTRIBUTES |
Attributes for the output SDE that can be used with LOCATIONS coordinates if wishing to build a vector point file for geographic data outside of this package. |
id |
Identifier for the SDE shape - it should be unique |
calccentre |
Boolean: TRUE if mean centre is computed |
weighted |
Boolean: TRUE if the weighted mean centre is to be used instead |
CENTRE.x |
X-coordinate of the centre |
CENTRE.y |
Y-coordinate of the centre |
Sigma.x |
Half-length of axis along x-axis |
Sigma.y |
Half-length of axis along y-axis |
Major |
String indicating which axis is the major elliptical axis |
Minor |
String indicating which axis is the minor elliptical axis |
Theta |
Rotation angle in degrees |
Eccentricity |
A measure of eccentricity (i.e., the flatness of the ellipse) |
Area.sde |
Area of the SDE |
TanTheta |
Trigonometric result |
SinTheta |
Trigonometric result |
CosTheta |
Trigonometric result |
SinThetaCosTheta |
Trigonometric result |
Sin2Theta |
Trigonometric result |
Cos2Theta |
Trigonometric result |
ThetaCorr |
Corrected theta angle for rotation of major axis from north |
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.
Tarmo K. Remmel, Randy Bui, Ron N. Buliung
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.
calc_box,
calc_sde,
calc_cmd,
calc_cf,
calc_cf2pts,
calc_mnc,
calc_mdc,
gridpts
# 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)# 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)
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).
data(centre)data(centre)
The format is a two-element vector of numeric entries.
The coordinates of the center must have the same units and projection as the remaining point observations.
This demonstration data has been manufactured for illustrative purposes only.
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.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.
Provides the functionality of cos, but for input angles measured in degrees (not radians).
cos_d(theta = 0)cos_d(theta = 0)
theta |
A numeric angular measurement in degrees from north. |
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.
Returns a numeric value for the cosine of the specified angular measurement
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.
Tarmo K. Remmel
sin_d, tan_d,
asin_d, acos_d,
atan_d
cos_d(theta = 90)cos_d(theta = 90)
Compute distances from a source location (point) to a series of destination locations (points).
distances(centre.xy = NULL, destmat = NULL, verbose = FALSE)distances(centre.xy = NULL, destmat = NULL, verbose = FALSE)
centre.xy |
Two-element vector containing x,y coordinates of the source location |
destmat |
Two-column matrix or data frame containing x,y coordinates of the activity locations |
verbose |
Boolean: Set to T if verbose output is desired |
Distance computations are strictly Euclidean between the source point and each destination point.
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.
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.
Tarmo K. Remmel
data(centre) data(activities) distances(centre.xy=centre, destmat=activities, verbose=FALSE)data(centre) data(activities) distances(centre.xy=centre, destmat=activities, verbose=FALSE)
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.
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, ...)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, ...)
datin |
Input data object; the result from calc_box() |
plotnew |
Boolean: Set to TRUE to create a new plot. Set to FALSE to overlay current plot. |
plothv |
Boolean: Set to TRUE if the orthogonal N-S, E-W axes are to be plotted through the centre |
plotweightedpts |
Boolean: Set to TRUE if the weighted point observations are to be plotted |
weightedpts.col |
Specify a colour for the weighted point observations |
weightedpts.pch |
Specify a plotting symbol for the weighted point observations |
plotpoints |
Boolean: Set to TRUE if the point observations are to be plotted |
points.col |
Specify a colour for the point observations |
points.pch |
Specify a plotting symbol for the point observations |
plotcentre |
Boolean: Set to TRUE if the mean/weighted/user-defined centre is to be plotted |
centre.col |
Specify a colour for the centre |
centre.pch |
Specify a plotting symbol for the centre |
titletxt |
A string to indicate the title for the plot |
xaxis |
A string to label the x-axis of the plot |
yaxis |
A string to label the y-axis of the plot |
box.col |
Specify a line colour for the SD Box |
box.lwd |
Specify a line width for the SD Box |
jpeg |
Boolean: Set to TRUE if the plot should be saved in JPEG format |
... |
Arguments to be passed to graphical parameters |
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.
This function returns a plot in the graphics device.
Tarmo K. Remmel, Randy Bui, Ron N. Buliung
# 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()# 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()
This function plots various centre of a set of point observations.
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", ...)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", ...)
datin |
List object of all calc_ function objects that you wish to plot. |
plotnew |
Boolean: Set to TRUE to create a new plot. Set to FALSE to overlay current plot. |
plotSDE |
Boolean: Set to TRUE if the centres for the SDE are to be plotted. |
xaxis |
A string to label the x-axis of the plot. |
yaxis |
A string to label the y-axis of the plot. |
plotweightedpts |
Boolean: Set to TRUE if the weighted point observations are to be plotted. |
weightedpts.col |
Specify a colour for the weighted point observations. |
weightedpts.pch |
Specify a plotting symbol for the weighted point observations. |
plotpoints |
Boolean: Set to TRUE if the point observations are to be plotted. |
points.col |
Specify a colour for the point observations. |
points.pch |
Specify a plotting symbol for the point observations. |
plotcentre |
Boolean: Set to TRUE if the mean/weighted/user-defined centre is to be plotted. |
centre.col |
Specify a colour for the centre. |
centre.pch |
Specify a plotting symbol for the centre. |
plotcentral |
Boolean: Set to TRUE if the central feature is to be highlighted |
central.col |
Specify a colour for the central feature. |
central.pch |
Specify a plotting symbol for the central feature. |
plotCF2PTS |
Boolean: Set to TRUE if the central feature between 2 point patterns is to be highlighted. |
CF2PTS.col |
Specify a colour for the central feature. |
CF2PTS.pch |
Specify a plotting symbol for the central feature. |
plotmedian |
Boolean: Set to TRUE if the median centre is to be plotted. |
median.col |
Specify a colour for the median centre. |
median.pch |
Specify a plotting symbol for the median centre. |
plotCMD |
Boolean: Set to TRUE if the centre of minimum distance is to be plotted. |
CMD.col |
Specify a colour for the centre of minimum distance. |
CMD.pch |
Specify a plotting symbol for the centre of minimum distance. |
TITLE |
A character string with the title for your plot. |
... |
Arguments to be passed to graphical parameters. |
The element FORPLOTTING contained within any of the calc function output lists is required as an argument for datin.
This function returns a plot in the graphics device.
Tarmo K. Remmel, Randy Bui, Ron N. Buliung
# 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)# 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)
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.
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, ...)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, ...)
datin |
Input data object; the result from calc_sdd() |
plotnew |
Boolean: Set to TRUE to create a new plot. Set to FALSE to overlay current plot. |
plothv |
Boolean: Set to TRUE if the orthogonal N-S, E-W axes are to be plotted through the centre |
plotweightedpts |
Boolean: Set to TRUE if the weighted point observations are to be plotted |
weightedpts.col |
Specify a colour for the weighted point observations |
weightedpts.pch |
Specify a plotting symbol for the weighted point observations |
plotpoints |
Boolean: Set to TRUE if the point observations are to be plotted |
points.col |
Specify a colour for the point observations |
points.pch |
Specify a plotting symbol for the point observations |
plotcentre |
Boolean: Set to TRUE if the mean/weighted/user-defined centre is to be plotted |
centre.col |
Specify a colour for the centre |
centre.pch |
Specify a plotting symbol for the centre |
titletxt |
A string to indicate the title on the plot |
xaxis |
A string to label the x-axis of the plot |
yaxis |
A string to label the y-axis of the plot |
sdd.col |
Specify a line colour for the SDD circle |
sdd.lwd |
Specify a line width for the SDD circle |
jpeg |
Boolean: Set to TRUE if the plot should be saved in JPEG format |
... |
Arguments to be passed to graphical parameters |
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.
This function returns a plot in the graphics device.
Tarmo K. Remmel, Randy Bui, Ron N. Buliung
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()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()
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.
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, ...)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, ...)
datin |
Input data object; the result from calc_sde() |
plotnew |
Boolean: Set to TRUE to create a new plot. Set to FALSE to overlay current plot. |
plotSDEaxes |
Boolean: Set to TRUE if the orthogonal axes through the centroid are to be plotted |
plotweightedpts |
Boolean: Set to TRUE if the weighted point observations are to be plotted |
weightedpts.col |
Specify a colour for the weighted point observations |
weightedpts.pch |
Specify a plotting symbol for the weighted point observations |
plotpoints |
Boolean: Set to TRUE if the point observations are to be plotted |
points.col |
Specify a colour for the point observations |
points.pch |
Specify a plotting symbol for the point observations |
plotcentre |
Boolean: Set to TRUE if the mean/weighted/user-defined centre is to be plotted |
centre.col |
Specify a colour for the centre |
centre.pch |
Specify a plotting symbol for the centre |
titletxt |
A string to indicate the title on the plot |
xaxis |
A string to label the x-axis of the plot |
yaxis |
A string to label the y-axis of the plot |
sde.col |
Specify a line colour for the SDE circle |
sde.lwd |
Specify a line width for the SDE circle |
jpeg |
Boolean: Set to TRUE if the plot should be saved in JPEG format |
... |
Arguments to be passed to graphical parameters |
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.
This function returns a plot in the graphics device.
Tarmo K. Remmel, Randy Bui, Ron N. Buliung
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()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()
Provides the functionality of sin, but for input angles measured in degrees (not radians).
sin_d(theta = 0)sin_d(theta = 0)
theta |
A numeric angular measurement in degrees from north. |
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.
Returns a numeric value for the sine of the specified angular measurement
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.
Tarmo K. Remmel
cos_d, tan_d,
asin_d, acos_d,
atan_d
sin_d(theta = 90)sin_d(theta = 90)
Provides the functionality of tan, but for input angles measured in degrees (not radians).
tan_d(theta = 0)tan_d(theta = 0)
theta |
A numeric angular measurement in degrees from north. |
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.
Returns a numeric value for the tangent of the specified angular measurement
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.
Tarmo K. Remmel
sin_d, cos_d,
asin_d, acos_d,
atan_d
tan_d(theta = 45)tan_d(theta = 45)
This is a single column vector for weighting the importance of point locations.
data(wts)data(wts)
A single column vector of numeric values.
The weights can be specified according to any reasonable criteria specified by the user
This demonstration data has been manufactured for illustrative purposes only.
data(wts) str(wts) plot(wts)data(wts) str(wts) plot(wts)