match.tol: Determine matching observation with a tolerance in time-scale

In pastecs: Package for Analysis of Space-Time Ecological Series

Determine matching observation with a tolerance in time-scale

Description

Determine which observations in a regular time series match observation in an original irregular one, accepting a given tolerance window in the time-scale. This function is internally used for regulation (functions regul(), regul.screen() and regul.adj()

Usage

match.tol(x, table, nomatch=NA, tol.type="both", tol=0)

Arguments

x	a numerical vector containing seeked values (time-scale of the regular series)
table	a numerical vector containing initial times to look for match in x
nomatch	the symbol tu use to flag an entry where no match is found. By default, nomatch=NA
tol.type	the type of adjustment to use for the time-tolerance: "left", "right", "both" (by default) or "none". If tol.type="left", corresponding x values are seeked in a window ]table-tol, table]. If tol.type="right", they are seeked in the window [table, table+tol[. If tol.type="both", then they are seeked in the window ]table-tol, table+tol]. If several observations are in this window, the closest one is used. Finally, if tol.type="none", then the function returns the nomatch symbol for all entries
tol	the tolerance in the time-scale to determine if a value in x matches a value in table. If tol=0, observations in each respective series must match exactly, otherwise observations in the regulated series are interpolated. tol must be a round fraction of the interval between observations in x (x[i+1] - x[i], (x[i+1] - x[i])/2, (x[i+1] - x[i])/3, etc...), and cannot be larger than it, otherwise, tol is automatically adjusted to the closest allowed value. By default, tol=NULL. This is equivalent to tol=0. Warning!

Value

a vector of the same length of x, indicating the position of the matching observations in table

Author(s)

Philippe Grosjean ([e-mail]), Frédéric Ibanez ([e-mail])

See Also

regul, regul.screen, regul.adj

Examples

X <- 1:5
Table <- c(1, 3.1, 3.8, 4.4, 5.1, 6)
match.tol(X, Table)
match.tol(X, Table, tol=0.2)
match.tol(X, Table, tol=0.55)

pastecs documentation built on May 29, 2024, 5:56 a.m.