Layer Contour Lines

This function is a wrapper around contourLines that adds the countourlines to a loon plot which is based on the cartesian coordinate system.

l_layer_contourLines(widget, x = seq(0, 1, length.out = nrow(z)),
  y = seq(0, 1, length.out = ncol(z)), z, nlevels = 10,
  levels = pretty(range(z, na.rm = TRUE), nlevels),
  asSingleLayer = TRUE, parent = "root", index = "end", ...)

Arguments

widget	widget path as a string or as an object handle
x	locations of grid lines at which the values in z are measured. These must be in ascending order. By default, equally spaced values from 0 to 1 are used. If x is a list, its components x$x and x$y are used for x and y, respectively. If the list has component z this is used for z.
y	see description for the x argument
z	a matrix containing the values to be plotted (NAs are allowed). Note that x can be used instead of z for convenience.
nlevels	number of contour levels desired iff levels is not supplied.
levels	numeric vector of levels at which to draw contour lines.
asSingleLayer	if TRUE a lines layer is used for the line, otherwise if FALSE a group with nested line layers for each line is created
parent	parent widget path
index	position among its siblings. valid values are 0, 1, 2, ..., 'end'
...	argumnets forwarded to l_layer_line

Value

layer id of group or lines layer

Details

For more information run: l_help("learn_R_layer.html#countourlines-heatimage-rasterimage")

Examples

p <- l_plot()
x <- 10*1:nrow(volcano)
y <- 10*1:ncol(volcano)
lcl <- l_layer_contourLines(p, x, y, volcano)
l_scaleto_world(p)

if (requireNamespace("MASS", quietly = TRUE)) {

  p1 <- with(iris, l_plot(Sepal.Length~Sepal.Width, color=Species))
  lcl <- with(iris, l_layer_contourLines(p1, MASS::kde2d(Sepal.Width,Sepal.Length)))

  p2 <- with(iris, l_plot(Sepal.Length~Sepal.Width, color=Species))
  layers <- sapply(split(cbind(iris, color=p2['color']), iris$Species), function(dat) {
       kest <- with(dat, MASS::kde2d(Sepal.Width,Sepal.Length))
       l_layer_contourLines(p2, kest, color=as.character(dat$color[1]), linewidth=2,
            label=paste0(as.character(dat$Species[1]), " contours"))
  })
}