iview: Visualisation shortcuts

In adeckmyn/meteogrid: Gridded meteorological data

Visualisation shortcuts

Description

Routines for visualisation of meteogrid objects. They use the meteogrid methods of image, contour, fcontour and vecplot.

Usage

iview(x,nlevels=15,color.palette=irainbow,
      levels=pretty(x[1:gdomain$nx,1:gdomain$ny], nlevels),
      col=color.palette(length(levels)-1),
      title=paste(attr(x,"info")$name,"\n",attr(x,"time")),
      legend=FALSE, mask=NULL, na.col=par("bg"),
      drawmap=TRUE, maplwd=.5, mapcol='black', map.database='world',
      interior=TRUE, fill=FALSE, ...)
cview(x,nlevels=15,
      title=paste(attr(x,"info")$name,"\n",attr(x,"time")),
      mask=NULL, add=FALSE,
      drawmap=!add, maplwd=.5, mapcol="black", map.database="world",
      interior=TRUE, fill=FALSE, ...)
fcview(x,nlevels=15,color.palette=irainbow,
       levels=pretty(x[1:gdomain$nx,1:gdomain$ny], nlevels),
       col=color.palette(length(levels)-1),
       title=paste(attr(x,"info")$name,"\n",attr(x,"time")),
       legend=TRUE,mask=NULL,
       drawmap=TRUE, maplwd=.5, mapcol='black', map.database='world',
      interior=TRUE, fill=FALSE, ...)
vview(U, V, add=FALSE, aspcorrect=TRUE,
      drawmap=TRUE, maplwd=.5, mapcol="black", map.database='world',
      interior=TRUE, fill=FALSE, ...)

Arguments

x	A geofield object.
U, V	geofield objects interpreted as U and V components of a wind field.
nlevels	Number of (colour) levels. You may also give the levels explicitely.
color.palette	Colours for the levels.
levels	A fixed set of breaks. If levels is defined, nlevels is ignored. If missing, the value range is devided in approximately nlevels breaks.
col	A fixed vector of colours. If provided, the length must be exactly equal to length(levels)-1. So it is only practicle to define this if you also have a fixed set of levels.
title	Title for the plot.
add	If TRUE, the plot is superposed on the current image,
mask	Defines a mask such that all grid points with mask==FALSE are set to NA. The mask may be a matrix with the same dimension as x, an expression involving x, or even a string that is parsed and which uses 'x' to represent the data.
na.col	By default, masked grid points (and any other NA values) are transparent. With na.col you can give them another colour.
legend	If TRUE, a color legend is drawn at the right of the image.
drawmap	If TRUE, a world map is superposed on the image.
fill	If TRUE, the map is drawn as filled polygons, not just lines. This is most interesting for contours and vectors, but may in rare cases be used with images, if the colours are transparent.
interior	If FALSE, the interior political borders are not drawn.
maplwd, mapcol	Line width and colour for the world map.
map.database	Which map data to use. Default is 'world' from the maps package.
aspcorrect	In Lat/Lon co-ordinates, the aspect ratio is not 1:1. If this argument is TRUE, a correction is attempted. For other projections, this argument is ignored.
...	Further options for limage, vecplot or contour.

Details

These functions are in fact simple "wrappers" for the more general functions limage etc. The (...) indicates any parameter that is accepted by these functions.

Value

An image (iview), contour (cview) or filled contour (fcview) plot of the data, overlaid by geographical boundaries. vview plots a vector field (e.g. wind).

See Also

limage,vecplot,contour

Examples

## Not run: 
# mask as a string that is evaluated literally (x is the input data)
iview(x=field,mask="x>0") # all negative values are left blank
# mask as an expression, assuming lsm is a known geofield
iview(x=field,mask=lsm) # all points where lsm=FALSE are left blank

## End(Not run)

adeckmyn/meteogrid documentation built on Jan. 13, 2025, 11:02 p.m.