aoristic - Generates Aoristic Probability Distributions
It can sometimes be difficult to ascertain when some
events (such as property crime) occur because the victim is not
present when the crime happens. As a result, police databases
often record a 'start' (or 'from') date and time, and an 'end'
(or 'to') date and time. The time span between these date/times
can be minutes, hours, or sometimes days, hence the term
'Aoristic'. Aoristic is one of the past tenses in Greek and
represents an uncertain occurrence in time. For events with a
location describes with either a latitude/longitude, or X,Y
coordinate pair, and a start and end date/time, this package
generates an aoristic data frame with aoristic weighted
probability values for each hour of the week, for each
observation. The coordinates are not necessary for the program
to calculate aoristic weights; however, they are part of this
package because a spatial component has been integral to
aoristic analysis from the start. Dummy coordinates can be
introduced if the user only has temporal data. Outputs include
an aoristic data frame, as well as summary graphs and displays.
For more information see: Ratcliffe, JH (2002) Aoristic
signatures and the temporal analysis of high volume crime
patterns, Journal of Quantitative Criminology. 18 (1): 23-43.
Note: This package replaces an original 'aoristic' package
(version 0.6) by George Kikuchi that has been discontinued with
his permission.