Convert sight distance and sight angle to perpendicular distance.

When distance data are collected on line transects using sight distances and sight angles, they need to be converted to perpendicular distances before analysis.

sight2perpdist(sightdist, sightangle)

Arguments

sightdist

Distance from observer

sightangle

Angle from center line. In degrees between 0 and 180.

Value

Perpendicular distance

See also

distsamp

Examples

round(sight2perpdist(10, c(0, 45, 90, 135, 180)))
#> [1]  0  7 10  7  0