calc_cf {aspace}

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

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

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:

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

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)