image_dataframe: Creates a color response map based on columnar data.
In forestgeo/ctfs: Tools for the Analysis of Forest Dynamics

Description Usage Arguments Details Examples

Creates a color response map based on columnar data, not a matrix as used by R's image function. It is used in cases where a full matrix of responses, over a complete grid, is not available. Data are submitted as a table with x and y coordinates, and a response z at each.

The points are mapped on an x-y plot, then colored according to the value of z. One typical use would be where soil data are available at many locations, coloring points by the concentration of one nutrient. Another, illustrated below, would be to color tree locations according to dbh.

image_dataframe(data, xcol = "x", ycol = "y", zcol = "z",
  breaks = NULL, div = NULL, colors = NULL, xname = "x",
  yname = "y", xrange = NULL, yrange = NULL, ptsize = 1,
  graphfile = NULL, export = X11, newgraph = FALSE, h = 11,
  w = 11, plotsize = 6)

`data`	A data frame with at least 3 columns, 2 of which are coordinates and one a numerical response at those coordinates
`xcol, ycol, zcol`	These allow the columns of data to carry non-standard names
`breaks`	if set, a vector of breaks for the image colors and the contour lines; if NULL, levels controls the breaks
`xname`	axis names
`yname`	axis names
`xrange, yrange`	Minimum and maximum x and y coordinates of area graphed. If `NULL`, all `x` (or `y`) are included.
`ptsize`	Passed to argument `cex` in `graphics::par()`.
`graphfile`	the file name if export is pdf, png, jpeg, win.metafile, etc.
`export`	if `newgraph = TRUE`, this defines the graphics device; options include X11, quartz, win.graph, win.metafile, png, bmp, jpeg, pdf (not quoted!)
`newgraph`	if FALSE, just graph to the screen and export is ignored; use TRUE to create a new plot window or export to a file.
`h`	height and width of graph window in units which depend on the export device chosen (some are pixels, some are inches); ignored if newgraph = FALSE.
`w`	height and width of graph window in units which depend on the export device chosen (some are pixels, some are inches); ignored if newgraph = FALSE.
`plotsize`	size of graph's x-dimension in inches; ignored if newgraph=FALSE

Other arguments are the same as imageGraph().

Name image.dataframe clashed with an S3 method, so it was replaced by image_dataframe.

## Not run: 
CTFSplot('bci',6,'full')

image_dataframe(
  data = subset(bciex::bci12t6mini, status == 'A'),
  xcol = 'gx',
  ycol = 'gy',
  zcol = 'dbh',
  breaks = c(10, 20, 50, 100, 500, 10000),
  xrange = c(0, 100),
  yrange = c(0, 100),
  colors = c('orange', 'yellow', 'lightgreen', 'green', 'blue'),
  newgraph = TRUE,
  h = 9,
  w = 12,
  plotsize = 7
)
## End(Not run)