从经度和纬度计算角度 [英] Calculating angle from latitude and longitude

问题描述

我有一组经度和纬度，所以这是动物随时间移动的数据.我想做的是计算转弯角度，即每次运动之间转过的角度.所以说我有点1，点2和点3，分别对应每个点的经度和纬度值(动物从点1到点2到点3等)，我想计算这3个点之间的角度2是中间点.我应该怎么办?我的操作系统是Windows，我正在使用R进行分析.

I have a set of latitudes and longitudes , so this is the data for an animal as it moves in time. what i want to do is to calculate turning angle, that is by what angle it turns between every movement. so say i have point 1, point 2 and point 3 with latitude and longitude value corresponding to each point(animal moves from point 1 to point 2 to point 3 and so on) and i want to calculate the angle between these 3 points, point 2 being the middle point. what should i do? my OS is windows and i am using R for analysis.

这是我的示例数据:

longitude                       latitude
36.89379547                0.290166977
36.89384037                0.290194109
36.88999724                0.286821044
36.88708721                0.288339411
36.88650313                0.29010232
36.88563203                0.289939416
36.88545224                0.290924863

它们以十进制度为单位

推荐答案

使用maptools中的trackAzimuth函数:

library(maptools)

trackAngle <- function(xy) {
    angles <- abs(c(trackAzimuth(xy), 0) -
                  c(0, rev(trackAzimuth(xy[nrow(xy):1, ]))))
    angles <- ifelse(angles > 180, 360 - angles, angles)
    angles[is.na(angles)] <- 180
    angles[-c(1, length(angles))]
}

trackAzimuth 函数是围绕 gzAzimuth 的简单循环包装.有关在球体上计算方向的参考，请参见?gzAzimuth .

The trackAzimuth function is a simple loop wrapper around gzAzimuth. See ?gzAzimuth for references on calculating directions on the sphere.

使用数据:

x <- read.table(text = "longitude                       latitude
36.89379547                0.290166977
36.89384037                0.290194109
36.88999724                0.286821044
36.88708721                0.288339411
36.88650313                0.29010232
36.88563203                0.289939416
36.88545224                0.290924863", header = TRUE)

trackAngle(as.matrix(x))
[1]  10.12946 111.17211 135.88514  97.73801  89.74684

我不得不从函数中删除第一个/最后一个角度，这是我在其他地方使用此函数之后所做的事情.应该是现在.:)

I had to remove first/last angles from the function, something I was doing after the fact with this function elsewhere. Should be right now. :)

此外，软件包 adehabitatLT 和 argosfilter 包含用于计算轨迹方向和角度的函数.

Also, the packages adehabitatLT and argosfilter contain functions to calculate track directions and angles.

这篇关于从经度和纬度计算角度的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！