mwinGrid {astrochron}

Determine 'dynamic moving window' for stratigraphic series, adjusting for changing sample density to maintain a window of constant duration; output on evenly spaced grid

Description

Determine start and end points for a moving window of fixed duration (e.g. 500 kiloyears). The dynamic window allows for adjustment of the number of data points in the window, so it has a constant duration in time or space. This version will output an evenly spaced spatial/temporal grid.

Usage

mwinGrid(dat,win,step,start=NULL,end=NULL,verbose=T)

Arguments

dat

Your data frame containing stratigraphic data; any number of columns (variables) are permitted, but the first column should be a location identifier (e.g., depth, height, time).

win

Moving window size in units of space or time.

step

Step size for moving window, in units of space or time.

start

Start moving window at what depth/height/time; by default will use first value

end

End moving window at what depth/height/time; by default will use last value

verbose

Verbose output? (T or F)

Details

This algorithm is similar to function mwin, but instead of stepping forward one stratigraphic datum at a time, it generates an evenly spaced spatial/temporal grid.

Value

A data frame containing: Starting index for window, Ending index for window, Location (center)

Examples

# generate some noise
ex1 <- ar1(npts=50,dt=1)

# jitter sampling times
ex1[1]=ex1[1]+rnorm(50,sd=0.25)
# sort 
ex1 = ex1[order(ex1[,1],na.last=NA,decreasing=FALSE),]

# run mwin
mwinGrid(ex1,win=10,step=2)