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

In AustralianAntarcticDivision/EchoviewR: Control of Echoview via COM

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

Description

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

Usage

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

Details

The call of zigzagSurvey has unrotated=FALSE

Value

Line transect coordinates as specified in zigzagSurvey

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))
 
## End(Not run)

AustralianAntarcticDivision/EchoviewR documentation built on Aug. 21, 2023, 6:56 p.m.