GEOmap (version 2.1)

GEOTOPO: 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

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

Details

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

See Also

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

Examples

library(geomapdata)


data(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 )