| Type: | Package |
| Title: | Determine Position of Observer |
| Version: | 0.5.0 |
| Date: | 2016-10-22 |
| Description: | Measuring angles between points in a landscape is much easier than measuring distances. When the location of three points is known the position of the observer can be determined based solely on the angles between these points as seen by the observer. This task (known as triangulation) however requires onerous calculations - these calculations are automated by this package. |
| License: | LGPL-2 | LGPL-2.1 | LGPL-3 [expanded from: LGPL] |
| LazyData: | TRUE |
| RoxygenNote: | 5.0.1 |
| NeedsCompilation: | no |
| Packaged: | 2016-10-29 11:30:16 UTC; mat |
| Author: | Mathias Milfeldt [aut, cre] |
| Maintainer: | Mathias Milfeldt <mathias@milfeldt.dk> |
| Repository: | CRAN |
| Date/Publication: | 2016-10-29 13:47:55 |
Determine angles as seen by observer
Description
Determine the angles (between three known points) as seen by an observer with a known position.
Usage
determine_angles(A, B, C, observer_position = c(0, 0), output_plot = TRUE,
lines_in_plot = TRUE, angles_in_plot = TRUE, decimals_in_plot = 2)
Arguments
A |
A point defined by a vector containing an x- and an y-coordinate |
B |
A point defined by a vector containing an x- and an y-coordinate |
C |
A point defined by a vector containing an x- and an y-coordinate |
observer_position |
A vector containing an x- and an y-coordinate |
output_plot |
Boolean variable indicating whether a plot should be created |
lines_in_plot |
Boolean variable indicating whether lines should be drawn in the plot |
angles_in_plot |
Boolean variable indicating whether the angles should be printet in the plot |
decimals_in_plot |
Integer indicating the number of decimals used |
Value
The angles as seen by the observer expressed in radians.
Examples
determine_angles(A = c(0, 0), B = c(10, 0), C = c(5, 5), observer_position=c(4,1))
determine_angles(A = c(0, 0), B = c(10, 0), C = c(5, 5), observer_position=c(4,40),
angles_in_plot = FALSE)
Determine position of observer
Description
Determine the position of an observer based on angles between three known points as seen by the observer.
At least two angles must be provided - preferably observer_angle_AB and observer_angle_AC
(since this combination allows for solutions outside the triangle formed by the points A, B and C)
Usage
determine_position(A, B, C, observer_angle_AB, observer_angle_AC,
observer_angle_BC = NA, output_plot = TRUE, lines_in_plot = TRUE,
coordinates_in_plot = TRUE, decimals_in_plot = 2)
Arguments
A |
A point defined by a vector containing an x- and an y-coordinate |
B |
A point defined by a vector containing an x- and an y-coordinate |
C |
A point defined by a vector containing an x- and an y-coordinate |
observer_angle_AB |
An angle (numeric) expressed in radians (or alternatively the symbol |
observer_angle_AC |
An angle (numeric) expressed in radians (or alternatively the symbol |
observer_angle_BC |
An angle (numeric) expressed in radians (or alternatively the symbol |
output_plot |
Boolean variable indicating whether a plot should be created |
lines_in_plot |
Boolean variable indicating whether lines should be drawn in the plot |
coordinates_in_plot |
Boolean variable indicating whether the coordinates should be printet in the plot |
decimals_in_plot |
Integer indicating the number of decimals used |
Value
Coordinates indicating the observers position. Note that several solutions might exist.
Examples
determine_position(A = c(0, 0), B = c(10, 0), C = c(5, 5 * 3^0.5), observer_angle_AB = pi * 2/3,
observer_angle_AC = pi * 1/2)
determine_position(A = c(0, 0), B = c(10, 0), C = c(5, 5), observer_angle_AB = pi * 5/6,
observer_angle_AC = pi * 1/2, observer_angle_BC = NA, lines_in_plot = FALSE)
determine_position(A = c(0, 0), B = c(10, 0), C = c(5, 5), observer_angle_AB = pi * 5/6,
observer_angle_AC = pi * 1/2, observer_angle_BC = pi * 2/3, lines_in_plot = FALSE)
Determine confidence region for position
Description
This function is similar to determine_position()except for the fact that it is assumed that the angles are subject to measurement error.
Hence a confidence region (error 'ellipse') is returned instead of an exact position.
Usage
determine_region(A, B, C, observer_angle_AB, observer_angle_AC,
angle_error = pi/24, number_of_points = 200, output_plot = TRUE,
lines_in_plot = FALSE, coordinates_in_plot = FALSE,
decimals_in_plot = 2)
Arguments
A |
A point defined by a vector containing an x- and an y-coordinate |
B |
A point defined by a vector containing an x- and an y-coordinate |
C |
A point defined by a vector containing an x- and an y-coordinate |
observer_angle_AB |
An angle (numeric) expressed in radians |
observer_angle_AC |
An angle (numeric) expressed in radians |
angle_error |
A numeric indicating the measurement error in radians |
number_of_points |
A numeric indicating the number of error points tested |
output_plot |
Boolean variable indicating whether a plot should be created |
lines_in_plot |
Boolean variable indicating whether lines should be drawn in the plot |
coordinates_in_plot |
Boolean variable indicating whether the coordinates should be printet in the plot |
decimals_in_plot |
Integer indicating the number of decimals used |
Value
Coordinates indicating the outer border of the confidence region. Note that several different regions may exist.
Examples
determine_region(A = c(0, 0), B = c(10, 0), C = c(5, 5 * 3^0.5), observer_angle_AB = pi * 2/3,
observer_angle_AC = pi * 1/2)
determine_region(A = c(0, 0), B = c(10, 0), C = c(5, 5), observer_angle_AB = pi * 5/6,
observer_angle_AC = pi * 1/2, lines_in_plot = FALSE)