smoothFlightsGrid: Spatial smoothing

In joergsteinkamp/FlightControl: Airplane flight track visualization

Description

An object produced by gridFlights is spatially interpolated to the whole rectangular extent. Four interplolation methods are implemented:

1. loess smoothest surface, not close to reality

2. gam smooth surface, closer to reality. For higher 'k' values closer to reality, but computation time increases, too.

3. krige 'Sph'

4. krige 'Gau'

Usage

smoothFlightsGrid(data, method = "loess", k = 5, ...)

Arguments

data	a SpatialPixelsDataFrame
method	interpolation method. One of 'loess' (default), 'gam', 'gau' or 'sph'
k	if method='gam' parameter for the smooth term in te
...	further parameters passed on to 'loess'.

Value

a SpatialPixelsDataFrame

Author(s)

Joerg Steinkamp [e-mail]

Examples

require(raster)
extent <- extent(c(7.25, 8.5, 49.5, 50.2))
N <- 750
set.seed(987654)
data <- data.frame(lon=rbeta(N, 5, 2) * (extent@xmax - extent@xmin) + extent@xmin,
                   lat=rbeta(N, 2.5, 2.5) * (extent@ymax - extent@ymin) + extent@ymin)
data$altitude = (data$lon - 7.9)^3 - 3 * (data$lon - 7.9) * (data$lat- 50)^2
fgrid = gridFlights(data, min)
res <- smoothFlightsGrid(fgrid, "loess")
names(res) <- "loess"
res2 <- smoothFlightsGrid(fgrid, "gam")
res@data$gam = res2@data$altitude
res2 <- smoothFlightsGrid(fgrid, "gau")
res@data$gau = res2@data$altitude
res2 <- smoothFlightsGrid(fgrid, "sph")
res@data$sph = res2@data$altitude
spplot(res)

joergsteinkamp/FlightControl documentation built on May 19, 2019, 3 p.m.