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performs a scatterplot

Usage

s.image(dfxy, z, xax = 1, yax = 2, span = 0.5, xlim = NULL, ylim = NULL, 
  kgrid = 2, scale = TRUE, grid = FALSE, addaxes = FALSE, cgrid = 0, 
  include.origin = FALSE, origin = c(0, 0), sub = "", csub = 1, 
  possub = "topleft", neig = NULL, cneig = 1, image.plot = TRUE, 
  contour.plot = TRUE, pixmap = NULL, contour = NULL, area = NULL, 
  add.plot = FALSE)

Arguments

dfxy

a data frame containing the two columns for the axes

z

a vector of values on the dfxy rows

xax

the column number of x in dfxy

yax

the column number of y in dfxy

span

the parameter alpha which controls the degree of smoothing

xlim

the ranges to be encompassed by the x-axis, if NULL they are computed

ylim

the ranges to be encompassed by the y-axis, if NULL they are computed

kgrid

a number of points used to locally estimate the level line through the nodes of the grid, used by kgrid*sqrt(length(z))

scale

if TRUE, data are centered and reduced

grid

if TRUE, the background grid is traced

addaxes

a logical value indicating whether the axes should be plotted

cgrid

a character size, parameter used with par("cex")* cgrid to indicate the mesh of the grid

include.origin

a logical value indicating whether the point "origin" should be belonged to the graph space

origin

the fixed point in the graph space, for example c(0,0) the origin axes

sub

a string of characters to be inserted as legend

csub

a character size for the legend, used with par("cex")*csub

possub

a string of characters indicating the sub-title position ("topleft", "topright", "bottomleft", "bottomright")

neig

an object of class neig

cneig

a size for the neighbouring graph lines used with par("lwd")*cneig

image.plot

if TRUE, the image is traced

contour.plot

if TRUE, the contour lines are plotted

pixmap

an object 'pixmap' displayed in the map background

contour

a data frame with 4 columns to plot the contour of the map : each row gives a segment (x1,y1,x2,y2)

area

a data frame of class 'area' to plot a set of surface units in contour

add.plot

if TRUE uses the current graphics window

Value

The matched call.

Author

Daniel Chessel

Examples

if(!adegraphicsLoaded()) {
  if(requireNamespace("splancs", quietly = TRUE)) {
    wxy <- data.frame(expand.grid(-3:3, -3:3))
    names(wxy) <- c("x", "y")
    z <- (1 / sqrt(2)) * exp(-(wxy$x ^ 2 + wxy$y ^ 2) / 2)
    par(mfrow = c(2, 2))
    s.value(wxy, z)
    s.image(wxy, z)
    s.image(wxy, z, kgrid = 5)
    s.image(wxy, z, kgrid = 15)
    par(mfrow = c(1, 1))
  }
  
  if (FALSE) { # \dontrun{
  data(t3012)
  if(requireNamespace("splancs", quietly = TRUE)) {
    par(mfrow = c(3, 4))
    for(k in 1:12)
      s.image(t3012$xy, scalewt(t3012$temp[, k]), kgrid = 3)
    par(mfrow = c(1, 1))
  }
      
  data(elec88)
  if(requireNamespace("splancs", quietly = TRUE)) {
    par(mfrow = c(3,4))
    for(k in 1:12)
      s.image(t3012$xy, scalewt(t3012$temp[, k]), kgrid = 3, sub = names(t3012$temp)[k],
        csub = 3, area = elec88$area)
    par(mfrow = c(1, 1))
  }
  } # }
}