GEOTOPO: Topographic Plot of geographic region

In GEOmap: Topographic and Geologic Mapping

Topographic Plot of geographic region

Description

Extract subset of a topographic database, interpolate and plot using the persp program.

Usage

GEOTOPO(TOPO, PLOC, PROJ, calcol=NULL, nx=500, ny=500, nb = 4, mb = 4, hb = 8, PLOT=TRUE)

Arguments

TOPO	list of x,y,z for a DEM
PLOC	Location list, includes vectors LON and Lat
PROJ	projection
calcol	color table for coloring elevations above sea level
nx	number of points in x grid, default=500
ny	number of points in y grid, default=500
nb	see function mba.surf, default = 4
mb	see function mba.surf, default = 4
hb	see function mba.surf , default= 8
PLOT	logical, TRUE=plot a map and return color map

Details

The return matrix PMAT is a rotation matrix used for adding geographic (projected) data onto the perspective plot.

ETOPO5 or ETOPO2 can be downloaded from and installed using these links: http://leesj.sites.oasis.unc.edu/FETCH/GRAB/RPACKAGES/ETOPO2.RData and http://leesj.sites.oasis.unc.edu/FETCH/GRAB/RPACKAGES/ETOPO5.RData

Value

PMAT	Matrix from persp, used for adding other geographic information
xo	x-coordinates
yo	y-coordinates
IZ	interpolated elevations
Cmat	matrix of RGB Colors
Dcol	dimensions of Cmat

Note

If PLOT is false the transform matrix PMAT and the color mapping matrix Cmat will be returned as NA. To create these for future plotting, use TOPOCOL or LandSeaCol functions. TOPOCOL simply assigns values above sea level with one color scale and those below with under water colors. LandSeaCol requires a coastal map and fills in land areas with terrain colors and sea areas with blue palette colors.

Author(s)

Jonathan M. Lees<jonathan.lees.edu>

See Also

subsetTOPO, TOPOCOL, LandSeaCol, settopocol, subsetTOPO, persp, DOTOPOMAPI

Examples

## Not run: 

library(geomapdata)

####  need to download and install ETOPO data
###   data(ETOPO5)
load(ETOPO5)
PLOC=list(LON=c(137.008, 141.000),LAT=c(34.000, 36.992),
            x=c(137.008, 141.000), y=c(34.000, 36.992) )

 PROJ = setPROJ(type=2, LAT0=mean(PLOC$y) , LON0=mean(PLOC$x) )
COLS = settopocol()
JMAT = GEOTOPO(ETOPO5, PLOC, PROJ, COLS$calcol, nx=1000, ny=1000, nb=8, mb=8, hb=12, PLOT=TRUE)

############  this plot can be duplicated by using the output or GEOTOPO


 PMAT = persp(JMAT$xo, JMAT$yo, JMAT$IZ$z, theta = 0, phi = 90, r=4000,
col=JMAT$Cmat[1:(JMAT$Dcol[1]-1), 1:(JMAT$Dcol[2]-1)] , scale = FALSE,
      ltheta = 120, lphi=60, shade = 0.75, border = NA, expand=0.001, box = FALSE )



## End(Not run)

GEOmap documentation built on Sept. 1, 2023, 5:09 p.m.