inlmisc (version 0.2.4)

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. The 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

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()