driftmap {GeoXp}R Documentation

Detection of an eventual trend

Description

The function `driftmap' creates a grid on the map and calculates the mean and median for each cell. The right plot (resp. left plot) represents means and medians calculated by row (resp. column).

Usage

driftmap(long, lat, var, interpol = 1,nuage = 0, carte = NULL, 
         lablong = "",lablat = "", labvar = "")

Arguments

long a vector $x$ of size $n$
lat a vector $y$ of size $n$
var a vector of numeric values of size $n$
interpol if 1, the mean and median calculated are linearly interpoled
nuage if 1, the individuals are also represented on the graphics
carte matrix with 2 columns for drawing spatial polygonal contours : $x$ and $y$ coordinates of the vertices of the polygon
lablong name of the x-axis that will be printed on the map
lablat name of the y-axis that will be printed on the map
labvar name of variable `var'

Details

Possibility to change the number of cells in the grid with the tcltk window, to interpolate the means and medians calculated (by default), to work on a rotated map. Notice that this is not an interactive function.

Value

No values returned, only drawing of a graphic.

Author(s)

Thomas-Agnan C., Aragon Y., Ruiz-Gazen A., Laurent T., Robidou L.

References

Aragon Yves, Perrin Olivier, Ruiz-Gazen Anne, Thomas-Agnan Christine (2006), ``Statistique et Econométrie pour données géoréférencées : modèles et études de cas''

See Also

angleplotmap,variocloudmap,{rotation}

Examples

# data auckland
data(auckland)
data(auck.polys)
contours.auckland<-polylist2list(auck.polys)
driftmap(auckland$Easting,auckland$Northing,auckland$Deaths.1977.85,
interpol=0,nuage=1,lablong="X",lablat="Y",labvar="Deaths.1977.85")

# data afcon
data(afcon)
driftmap(afcon$x,afcon$y,afcon$totcon,interpol=0,
nuage=1,lablong="X",lablat="Y",labvar="Number of conflicts")

# data meuse
data(meuse.all)
data(meuse.riv)
driftmap(meuse.all$x,meuse.all$y,meuse.all$copper,
nuage=1,lablong="X",lablat="Y",
labvar="Concentration de cuivre (en ppm)")

[Package GeoXp version 1.0 Index]