OceanView (version 1.0.2)

Tracers in 2D: Plots tracer distributions in 2-D.

Description

tracers2D plots a tracer distribution using traditional R graphics. The topography can be defined when calling this function. tracers2Drgl plots a tracer distribution in open-GL graphics. A suitable topography has to be created before calling this function.

Usage

tracers2D(x, y, colvar = NULL, ..., 
          col = NULL, NAcol = "white", colkey = NULL, 
          mask = NULL, image = FALSE, contour = FALSE, 
          clim = NULL, clab = NULL) 

tracers2Drgl(x, y, colvar = NULL, ..., 
          col = NULL, NAcol = "white", clim = NULL)

Arguments

x, y

Vectors with x- and y-coordinates of the tracers. Should be of equal length.

colvar

The variable used for coloring. It need not be present, but if specified, it should be a vector of dimension equal to x. Values of NULL, NA, or FALSE will toggle off coloration a

col

Colors to be used for coloring each individual point (if colvar not specified) or that define the colors as specified by the colvar variable. If col is NULL and colvar is specified,

NAcol

Colors to be used for colvar values that are NA.

colkey

A logical, NULL (default), or a list with parameters for the color key (legend). List parameters should be one of side, plot, length, width, dist, shift, addlines, col.clab, cex.clab, side.clab, line.clab

contour, image

If TRUE, then a contour2D or image2D plot will be added to the quiver plot. Also allowed is to pass a list with arguments for the

clim

Only if colvar is specified, the range of the colors, used for the color key.

clab

Only if colkey is not NULL or FALSE, the label to be written on top of the color key. The label will be written at the same level as the main title. To lower it, clab can be made a ve

mask

A list defining the grid cells outside the domain as NA. Use a list with argument NAcol to specify the color that the masked cells (that are NA) should get; the default is "

...

additional arguments passed to the plotting method scatter2D. The arguments after ...must be matched exactly.

Value

• returns nothing

See Also

tracers3D for plotting time series of tracer distributions in 3D Ltrans for the output of a particle tracking model

Examples

# save plotting parameters
 pm <- par("mfrow")

## =======================================================================
## Create topography, data
## =======================================================================

# The topographic surface
 x <-  seq(-pi, pi, by = 0.2)
 y <-  seq(0, pi, by = 0.1)
 M <- mesh(x, y)
 z <- with(M, sin(x)*sin(y))

# Initial condition
 xi <- c(0.125 * rnorm(100) - pi/2, 0.125 * rnorm(100) - pi/4)
 yi <- 0.25 * rnorm(200) + pi/2

# the species
 species <- c(rep(1, 100), rep(2, 100))   

# set initial conditions 
 xp <- xi; yp <- yi

## =======================================================================
## using a mask and contour
## =======================================================================

 Z <- z; Z[abs(Z) < 0.1] <- NA
 par(mfrow = c(2, 2))

 for (i in 1:4) {
  # update tracer distribution
   xp <- xp + 0.25 * rnorm(200)
   yp <- yp + 0.025 * rnorm(200) 
  
  # plot new tracer distribution
   tracers2D(xp, yp, colvar = species, pch = ".", cex = 5, 
     main = paste("timestep ", i), col = c("orange", "blue"), 
     colkey = list(side = 1, length = 0.5, labels = c("sp1","sp2"),
     at = c(1.25, 1.75), dist = 0.075), NAcol = "black", 
     mask = list(x = x, y = y, z = Z), 
     contour = list(x = x, y = y, z = Z) )
 }

## =======================================================================
## using image and contour
## =======================================================================

 for (i in 1:4) {
  # update tracer distribution
   xp <- xp + 0.25 * rnorm(200)
   yp <- yp + 0.025 * rnorm(200) 
  
  # plot new tracer distribution
   tracers2D(xp, yp, colvar = species, pch = ".", cex = 5, 
     main = paste("timestep ", i), col = c("orange", "blue"), 
     colkey = list(side = 1, length = 0.5, labels = c("sp1","sp2"),
     at = c(1.25, 1.75), dist = 0.075), NAcol = "black", 
     contour = list(x = x, y = y, z = z),
     image = list(x = x, y = y, z = z, colkey = TRUE))
 }

## =======================================================================
## rgl tracer plot
## =======================================================================

# here the image has to be drawn first
 image2Drgl(x = x, y = y, z = z)

# set initial conditions 
 xp <- xi; yp <- yi
 nstep <- 40
 for (i in 1:nstep) {
  # update tracer distribution
   xp <- xp + 0.25 * rnorm(200)
   yp <- yp + 0.025 * rnorm(200) 
  
  # plot new tracer distribution                                                              n
   tracers2Drgl(xp, yp, colvar = species,  cex = 1,
     main = paste("timestep ", i), col = c("orange", "blue"))

 }

# reset plotting parameters
 par(mfrow = pm)