a numerical vector containing seeked values (time-scale of the regular series)

a numerical vector containing initial times to look for match in x

the symbol tu use to flag an entry where no match is found. By default, nomatch=NA

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

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!