centreLawnOnPosition: Centre a regular rectangular survey on a given position

In AustralianAntarcticDivision/EchoviewR: Control of Echoview via COM

Centre a regular rectangular survey on a given position

Description

Centres a regular rectangular survey on a desired latitude and longitude

Usage

centreLawnOnPosition(
  centreLon,
  centreLat,
  proj4string = NULL,
  tolerance = 20,
  ...
)

Arguments

centreLon	Desired centre location of survey
centreLat	Desired centre location of survey
proj4string	projection string of class CRS-class. If NULL defaults to "+proj=longlat +datum=WGS84"
tolerance	maximum distance (in metres) between desired survey centre and realised survey centre
...	other arguments to be passed into lawnSurvey

Value

Line transect coordinates (lon, lat) as specified in lawnSurvey

Examples

## Not run: 
coords=centreLawnOnPosition(centreLon=-170,centreLat=-60,lineLengthkm=2,lineSpacingkm=0.5,
startBearingdeg=30,numOfLines=5)
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(-170,-60,col='purple',pch=19,cex=2)
points(geomean(coords),col='red',pch=19,cex=1)
legend('bottomright',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.