Centre an zig-zag line transect survey on a given position

Centres a zig-zag survey on a desired latitude and longitude

centreZigZagOnPosition(centreLon, centreLat,
  proj4string = CRS("+proj=longlat +datum=WGS84"), tolerance = 20, ...)

Arguments

centreLon	Desired centre location of survey
centreLat	Desired centre location of survey
proj4string	projection string of class CRS-class
tolerance	maximum distance (in metres) between desired survey centre and realised survey centre
...	other arguments to be passed into \linkzigzagSurvey

Value

Line transect coordinates as specified in zigzagSurvey

Details

The call of zigzagSurvey has unrotated=FALSE

Examples

# NOT RUN {
coords=centreZigZagOnPosition(centreLon=-33,centreLat=-57,lineLengthkm=60,startBearingdeg=30,
rotationdeg=10,numOfLines=21)
plot(0,0,xlim=range(coords[,1]),ylim=range(coords[,2]),
type='n',xlab='Longitude, deg',ylab='Latitude, deg')
arrows(x0=coords[1:(nrow(coords)-1),1], y0=coords[1:(nrow(coords)-1),2],
      x1 = coords[2:nrow(coords),1], y1 = coords[2:nrow(coords),2])
text(coords,row.names(coords),cex=0.6)
points(coords[1,1],coords[1,2],col='blue',pch=17,cex=2)
points(coords[nrow(coords),1],coords[nrow(coords),2],col='blue',pch=15,cex=2)
points(-100,-60,col='purple',pch=19,cex=2)
points(geomean(coords),col='red',pch=19,cex=1)
legend('topright',c('Beginning','End','Desired centre','Actual centre'),
 col=c('blue','blue','purple','red'),pch=c(17,15,19,19),pt.cex=c(1,1,2,1))

# }