inlmisc (version 0.3.2)

PlotCrossSection: Plot Method for Cross Sections

Description

This function creates a cross-section view of raster data. A key showing how the colors map to raster values is shown below the map. The width and height of the graphics region will be automagically determined in some cases.

Usage

PlotCrossSection(transect, rs, geo.lays = names(rs), val.lays = NULL,
  wt.lay = NULL, asp = 1, ylim = NULL, max.dev.dim = c(43, 56),
  n = NULL, breaks = NULL, pal = NULL, col = NULL, ylab = NULL,
  unit = NULL, id = c("A", "A'"), labels = NULL, explanation = NULL,
  features = NULL, max.feature.dist = Inf, draw.key = TRUE,
  draw.sep = TRUE, is.categorical = FALSE, contour.lines = NULL,
  bg.col = "#E1E1E1", wt.col = "#FFFFFFD8", file = NULL)

Arguments

transect

'SpatialLines'. Piecewise linear transect line.

rs

'RasterStack'. Collection of RasterLayer objects with the same extent and resolution.

geo.lays

'character'. Vector of names in rs that specify the geometry raster layers; these must be given in decreasing order, that is, from the upper most (such as land surface) to the lowest (such as a bedrock surface).

val.lays

'character'. Vector of names in rs that specify the value raster layers (optional). Values from the first layer are mapped as colors to the area between the first and second geometry layers; the second layer mapped between the second and third geometry layers, and so on.

wt.lay

'character'. The name in rs that specifies the water-table raster layer (optional).

asp

'numeric'. y/x aspect ratio for spatial axes. Defaults to 1 (one unit on the x-axis equals one unit on the y-axis) when r is projected, otherwise, a calculated value based on axes limits is used.

ylim

'numeric'. Vector of length 2 giving the minimum and maximum values for the y-axis.

max.dev.dim

'numeric'. Vector of length 2 giving the maximum width and height for the graphics device in picas, respectively. Suggested dimensions for single-column, double-column, and sidetitle figures are c(21, 56), c(43, 56), and c(56, 43), respectively. This argument is only applicable when the file argument is specified.

n

'integer'. Desired number of intervals to partition the range of raster values (optional).

breaks

'numeric'. Vector of break points used to partition the colors representing numeric raster values (optional).

pal

'function'. Color palette to be used to assign colors in the plot, rainbow by default.

col

'character'. Vector of colors to be used in the plot. This argument requires breaks specification for numeric raster values and overrides any palette function specification. For numeric values there should be one less color than breaks. Categorical data require a color for each category.

ylab

'character'. Label for the y axis.

unit

'character'. Label for the measurement unit of the x- and y-axes.

id

'character'. Vector of length 2 giving the labels for the end points of the transect line, defaults to A--A'.

labels

'list'. Describes the location and values of labels in the color key. This list may include components at and labels.

explanation

'character'. Label explaining the raster cell value.

features

'SpatialGridDataFrame'. Point features adjacent to the transect line that are used as reference labels for the upper geometry layer.

max.feature.dist

'numeric'. Maximum distance from a point feature to the transect line, specified in the units of the rs projection.

draw.key

'logical'. If true, a color key should be drawn.

draw.sep

'logical'. If true, lines separating geometry layers are drawn.

is.categorical

'logical'. If true, cell values in val.lays represent categorical data; otherwise, these data values are assumed continuous.

contour.lines

'list'. If specified, contour lines are drawn. The contours are described using a list of arguments supplied to contour. Passed arguments include "drawlables", "method", and "col".

bg.col

'character'. Color used for the background of the area below the upper geometry raster layer.

wt.col

'character'. Color used for the water-table line.

file

'character'. Name of the output file. Specifying this argument will start a graphics device driver for producing a PDF or PNG file format---the file extension determines the format type. The width and height of the graphics region will be automagically determined and included with the function's returned values, see "Value" section for details; these device dimensions can be useful when creating similar map layouts in dynamic reports.

Value

Used for the side-effect of a new plot generated. Returns a 'list' object with the following graphical parameters:

din

device dimensions (width, height), in inches.

usr

extremes of the coordinates of the plotting region (x1, x2, y1, y2).

heights

relative heights on the device (upper, lower) for the map and color-key plots.

See Also

AddScaleBar, AddColorKey, ExtractAlongTransect

Examples

# NOT RUN {
data(volcano, package = "datasets")
x <- seq(from = 2667405, length.out = 61, by = 10)
y <- seq(from = 6478705, length.out = 87, by = 10)
r1 <- raster::raster(volcano, xmn = min(x), xmx = max(x), ymn = min(y),
                     ymx = max(y), crs = sp::CRS("+init=epsg:27200"))
r2 <- min(r1[]) - r1 / 10
r3 <- r1 - r2
rs <- raster::stack(r1, r2, r3)
names(rs) <- c("r1", "r2", "r3")

xy <- rbind(c(2667508, 6479501), c(2667803, 6479214), c(2667508, 6478749))
transect <- sp::SpatialLines(list(sp::Lines(list(sp::Line(xy)), ID = "Transect")),
                             proj4string = raster::crs(rs))

raster::plot(r1)
lines(transect)
raster::text(as(transect, "SpatialPoints"), labels = c("A", "BEND", "A'"),
             cex = 0.7, pos = c(3, 4, 1), offset = 0.1, font = 4)

explanation <- "Vertical thickness between layers, in meters."
PlotCrossSection(transect, rs, geo.lays = c("r1", "r2"), val.lays = "r3",
                 ylab="Elevation", asp = 5, unit = "METERS", explanation = explanation)

val <- PlotCrossSection(transect, rs, geo.lays = c("r1", "r2"), val.lays = "r3",
                        ylab="Elevation", asp = 5, unit = "METERS",
                        explanation = explanation, file = "Rplots.png")
print(val)

file.remove("Rplots.png")
graphics.off()

# }