Functions for manipulating data where the first and last appearances of taxa
are known from bounded intervals of time. The two main functions listed here
are for converting between (1)
a data structure consisting of a single 'flat' table where each taxon is listed as a
set of four dates (a
fourDate data type), and (2) a list format where each taxon
is listed as its first and last intervals, with an associated table of age bounds for
the intervals referred to in the first table (referred to as a
structure by many
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A list composed of two matrices with two columns each, the first giving interval start and end date bounds, and the second giving taxon first and last interval appearances in reference to the intervals listed in the first matrix.
A four column matrix where each row is a different taxon, the first two columns are the lower and upper bounds on the time of first appearance for that taxon and the third and fourth columns are respectively the lower and upper bounds on the time of last appearance for that taxon, all in time before present.
timeList2fourDate is for converting from a
timeList format to
fourDate2timeList is for converting from
fourDate format to a
A converted data object, respective to the function applied.
David W. Bapst
See my recent blog post on temporal datasets in paleontology for some details:
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#timeList object from the retiolinae dataset data(retiolitinae) str(retioRanges) taxicDivDisc(retioRanges) fourDateRet<-timeList2fourDate(retioRanges) # total uncertainty in retio first and last appearances? sum((fourDateRet[,1]-fourDateRet[,2])+(fourDateRet[,3]-fourDateRet[,4])) #convert back newTimeList<-fourDate2timeList(fourDateRet) taxicDivDisc(retioRanges)