strattotimeratecont {DAIME} | R Documentation |
This function transforms a given continuous stratigraphic rate/signal into the corresponding temporal rate/signal. The transformation is based on the age model constructed from the deposition rate.
This can for example be used to reconstruct the patterns of (first/last) fossil occurrences in time, given a given depositional environment.
strattotimeratecont(xdep, ydep, xsig, ysig, pos = NULL, hiatuslist = list(), unit = "sediment per time")
xdep |
Vector of strictly increasing real numbers |
ydep |
Vector of the same length of |
xsig |
Vector of strictly increasing real numbers |
ysig |
Vector of the same length of |
pos |
OPTIONAL. Vector of points in stratigrapic height that will be transformed into time, and determine where the temporal rate is evaluated. Default setting is a vector spanning the interval of interest with evenly spaced points (no. is chosen by the code) |
hiatuslist |
OPTIONAL, default is an empty list. A list of hiatuses to insert. Every entry in the list corresponds to a hiatus, which is given as a vector of length two. The first entry of the vector is the stratigraphic height of the hiatus, the second entry is the duration of the hiatus. |
unit |
OPTIONAL, default is "sediment per time". Either "sediment per time" or "time per sediment". Determines the unit that is assumed for the deposition rate. |
Returns a list containing
time |
vector containing times |
val |
vector containign the values of the temporal rate/signal at the times given by the first entry of the list |
The temporal rate is then approximated by approxfun(output$time,output$val)
. Output of NA
indicates that some values coincide with a hiatus or are located at places where the deposition rate/stratigraphic rate are undefined.
Niklas Hohmann
Hohmann, Niklas. 2018. Quantifying the Effects of Changing Deposition Rates and Hiatii on the Stratigraphic Distribution of Fossils. <doi:10.13140/RG.2.2.23372.51841>
timetostratratecont
for the transformation of rates from time into stratigraphic height,
strattotimepointcont
for the transformation of single samples or isotope ratios from stratigraphic height into time.
For an overview of the functions in the DAIME package, see its vignette (available via vignette("DAIME")
)
##define deposition rate and stratigraphic rate xdep=seq(0,12,length.out=100) ydep=splinefunH(x=c(0,2,4,6,8,10,12),y=c(1,5,6,1,0.5,1,6),m=c(0,1.5,-0.5,-0.5,0,0.5,0))(xdep) usedunit="sediment per time" #unit of deposition rate is sediment per time unit (default setting) #Plot deposition rate plot(xdep,ydep,type='l',main='Deposition Rate',xlab='Stratigraphic Height', ylab=usedunit) #define a rate ("signal") xsig= seq(from=min(xdep),to=max(xdep),length.out=100) ysig=splinefunH(x=c(0,4,12),y=c(0.5,2,0.5),m=c(0,0,0))(xsig) #function values of the signal plot(xsig,ysig,type='l',main='Stratigraphic Signal/Rate', xlab='Stratigraphic Height',ylab='Stratigraphic Rate') ##transform stratigraphic rate into temporal rate usedunit="sediment per time" #unit of deposition rate is sediment per time unit (default setting) reslist=strattotimeratecont(xdep,ydep,xsig,ysig,unit=usedunit) #plot temporal rate (transformed stratigrapic rate) plot(reslist$time,reslist$val,type='l',xlab='Time',ylab='temporal rate', main=paste('deposition rate interpreted as',usedunit)) #now using same input, but different interpretation of units usedunit="time per sediment" #now interpret the deposition rate in different units reslist=strattotimeratecont(xdep,ydep,xsig,ysig,unit=usedunit) #plot temporal rate (transformed stratigrapic rate) plot(reslist$time,reslist$val,type='l',xlab='Time',ylab='temporal rate', main=paste('deposition rate interpreted as',usedunit)) #note how different the results look!! #Insert hiatus stratigraphicheight=5 #strat. height of the hiatus duration=4 #duration of the hiatus hiatuslist=list(c(stratigraphicheight,duration)) #required input format for hiatuses reslist=strattotimeratecont(xdep,ydep,xsig,ysig,hiatuslist=hiatuslist) #unit is back to default plot(reslist$time,reslist$val,xlab='Time',ylab='Intensity',main='Temporal Rate/Signal') #hiatus is approx between 2 and 5