trip (version 1.1-21)

tripGrid: Generate a grid of time spent by line-to-cell gridding

Description

Create a grid of time spent from an object of class trip by exact cell crossing methods, weighted by the time between locations for separate trip events.

Usage

tripGrid(x, grid = NULL, method = "pixellate", ...)

Arguments

x

object of class trip

grid

GridTopology - will be generated automatically if NULL

method

pixellate or density

...

pass arguments to density.psp if that method is chosen (and temporary mechanism to direct users of legacy methods to tripGrid.interp)

Value

tripGrid returns an object of class SpatialGridDataFrame, with one column "z" containing the time spent in each cell in seconds.

Details

Zero-length lines cannot be summed directly, their time value is summed by assuming the line is a point. A warning is given. The density method returns proportionate values, not summed time durations.

See pixellate.psp and pixellate.ppp for the details on the method used. See density.psp for method="density".

Trip events are assumed to start and end as per the object passed in. To work with inferred "cutoff" positions see split.trip.exact.