s.image {adegraphics}

2-D scatter plot with loess estimation of an additional numeric score (levelplot)

Description

This function represents a two dimensional scatter plot with a continuous convex colored surface and/or contour lines representing a third variable.

Usage

s.image(dfxy, z, xax = 1, yax = 2, span = 0.5, gridsize = c(80L, 80L), 
  contour = TRUE, region = TRUE, outsideLimits = NULL, breaks = NULL,
  nclass = 8, col = NULL, facets = NULL, 
  plot = TRUE, storeData = TRUE, add = FALSE, pos = -1, ...)

Arguments

dfxy

a data frame used to produce the plot

z

a vector (or a matrix) of values on the dfxy rows

xax

an integer (or a vector) indicating which column(s) of dfxy is(are) plotted on the x-axis

yax

an integer (or a vector) indicating which column(s) of dfxy is(are) plotted on the y-axis

span

a value to control the degree of smoothing

gridsize

a 1 or 2-length vector indicating the cell numbers (horizontally and vertically) of the grid for the colored surface

contour

a logical to draw contour lines

region

a logical to fill inter-contour regions

breaks

a vector of values to split z. If NULL, pretty(z, nclass) is used.

nclass

an integer for the number of desired intervals, ignored if breaks is not missing.

outsideLimits

specific limits for the surface as a set of polygons. It must be an SpatialPolygons object. Hole are authorized.

col

a color or a colors vector used for the colored cells

facets

a factor splitting the rows of dfxy so that subsets of the data are represented on different sub-graphics

plot

a logical indicating if the graphics is displayed

storeData

a logical indicating if the data should be stored in the returned object. If FALSE, only the names of the data arguments are stored

add

a logical. If TRUE, the graphic is superposed to the graphics already plotted in the current device

pos

an integer indicating the position of the environment where the data are stored, relative to the environment where the function is called. Useful only if storeData is FALSE

...

additional graphical parameters (see adegpar and trellis.par.get)

Value

An object of class ADEg (subclass S2.image) or ADEgS (if add is TRUE and/or if facets or multidimensional z or vectors for xax/yax are used).
The result is displayed if plot is TRUE.

Author(s)

Alice Julien-Laferriere, Aurelie Siberchicot [e-mail] and Stephane Dray

See Also

S2.image ADEg.S2

Examples

df1 <- data.frame(expand.grid(-3:3, -3:3))
names(df1) <- c("x", "y")
z1 <- (1 / sqrt(2)) * exp(-(df1$x ^ 2 + df1$y ^ 2) / 2)
g1 <- s.image(df1, z1)

# add a continuous color bar as legend
# update(g1, plegend.drawColorKey = TRUE)

g2 <- s.image(df1, z1, gridsize = 50)

g3 <- s.image(df1, z1, gridsize = 100)
## g4 <- s.image(df1, z1, gridsize = 1000, plot = FALSE)

## Not run: 
  if(require(splancs, quietly = TRUE) & require(sp, quietly = TRUE)) {
    Sr1 <- Polygon(cbind(c(0, 1, 2, 1, 2, 0, -2, -1, -2, -1, 0), 
      c(2.5, 1.5, 2, 0, -2, -1, -2, 0, 2, 1.5, 2.5)))
    Sr2 <- Polygon(cbind(c(-0.5, 0.5, 0.5, -0.5, -0.5), c(0, 0, 1 ,1, 0)), hole = TRUE)
    Srs2 <- Polygons(list(Sr1, Sr2), ID = "star and hole")
    SPp <- SpatialPolygons(list(Srs2))
    df2 <- cbind(c(rnorm(2000, 1, 0.25), rnorm(3000, -1, 1.5)), c(rnorm(2000, 1, 0.5), 
      rnorm(3000, -1, 3)))
    z2 <- c(rnorm(2000, 12, 1), rnorm(3000, 1, 2))
    g5 <- s.image(df2, z2, outsideLimits = SPp, grid = 200, xlim = c(-2.5, 2.5), 
      ylim = c(-2, 3), ppalette.quanti = colorRampPalette(c(grey(0.1), grey(0.9))))
  
    data(t3012, package = "ade4")  
    g6 <- s.image(t3012$xy, ade4::scalewt(t3012$temp), porigin.include = FALSE)
    g7 <- s.image(t3012$xy, ade4::scalewt(t3012$temp), outsideLimits = t3012$Spatial, 
      Sp = t3012$Spatial)
  }

## End(Not run)