histomap: Interactive Histogram and map
In GeoXp: Interactive exploratory spatial data analysis

Description Usage Arguments Details Value Author(s) References See Also Examples

The function histomap() draws a histogram of a given variable name.var and a map with sites of coordinates coordinates(sp.obj). Each site is associated to a value of name.var and there is interactivity between the two windows.

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histomap(sp.obj, name.var, nbcol=10, type = c("count","percent", "density"),
names.attr=names(sp.obj), criteria=NULL, carte=NULL, identify=FALSE, cex.lab=0.8, 
pch=16, col="lightblue3", xlab="", ylab="", axes=FALSE, lablong="", lablat="")

`sp.obj`	object of class extending Spatial-class
`name.var`	a character; attribute name or column number in attribute table
`nbcol`	number of cells for histogram (10 by default)
`type`	Character string indicating type of histogram to be drawn. "percent" and "count" give relative frequency and frequency histograms, "density" produces a density scale histogram.
`names.attr`	names to use in panel (if different from the names of variable used in sp.obj)
`criteria`	a vector of size n of boolean which permit to represent preselected sites with a cross, using the tcltk window
`carte`	matrix with 2 columns for drawing spatial polygonal contours : x and y coordinates of the vertices of the polygon
`identify`	if not FALSE, identify plotted objects (currently only working for points plots). Labels for identification are the row.names of the attribute table row.names(as.data.frame(sp.obj)).
`cex.lab`	character size of label
`pch`	16 by default, symbol for selected points
`col`	"lightblue3" by default, color of bars on the histogram
`xlab`	a title for the graphic x-axis
`ylab`	a title for the graphic y-axis
`axes`	a boolean with TRUE for drawing axes on the map
`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

Sites selected by a bar on the histogram are represented on the map in red and the values of sites selected on the map by ‘points’ or ‘polygon’ are represented in red as a sub-histogram on the histogram.

In the case where user click on save results button, a vector of integer is created as a global variable in last.select object. It corresponds to the number of spatial units selected just before leaving the Tk window.

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

Thibault Laurent, Anne Ruiz-Gazen, Christine Thomas-Agnan (2012), GeoXp: An R Package for Exploratory Spatial Data Analysis. Journal of Statistical Software, 47(2), 1-23.

Roger S.Bivand, Edzer J.Pebesma, Virgilio Gomez-Rubio (2009), Applied Spatial Data Analysis with R, Springer.

histomap, histobarmap, scattermap, densitymap

######
# data oldcol
require("maptools")
example(columbus)

# columbus is included in the Spatial-Class object
# a very simple use of histomap :
histomap(columbus,"CRIME")

######
# data on price indices of real estate in France
data(immob)

# immob is a data.frame object. We have to create
# a Spatial object, by using first the longitude and latitude
# to create Spatial Points object ...
immob.sp = SpatialPoints(cbind(immob$longitude,immob$latitude))
# ... and then by integrating other variables to create SpatialPointsDataFrame
immob.spdf = SpatialPointsDataFrame(immob.sp, immob)
# we just give names to the spatial units...
row.names(immob.spdf)<-immob$Nom
# For more details, see vignette('sp', package="sp")

# optional : we add some contours that don't correspond to the spatial unit
# but are nice for mapping
midiP <- readShapePoly(system.file("shapes/region.shp", package="GeoXp")[1])
cont_midiP<-spdf2list(midiP[-c(22,23),])$poly

# A basic call of histomap function
histomap(immob.spdf,"prix.vente", carte= cont_midiP, identify=TRUE, cex.lab=0.6)

# ... with all options
histomap(immob.spdf,7, nbcol=15, type = "percent",
names.attr=names(immob), criteria=immob$rentabilite>5, carte=cont_midiP,
identify=TRUE, cex.lab=0.5, pch=12, col="pink",
xlab="variation price", ylab="percent", axes=TRUE, lablong="x",
lablat="y")