如何在两个已知点之间生成坐标 [英] How to generate coordinates in between two known points

问题描述

背景：

我正在使用运输路线，而Google提供的路线点足够远以创建形状。这些是您在Google地图中看到的巴士/火车路线。

我的要求：

Google的观点足以创造出直线。然而，我想要每一个点，比如5米。

问题：

所以，说我有两点[拉特，长]：

[ - 33.8824219918503,151.206686052582]和[-33.8815434600467,151.206556440037]

给出这两点我可以计算它们之间的距离。我们可以想象这两点之间的假想直线。

如何为每个5米的假想线生成坐标？ 解决方案

p> 给定距离和方位的起始点< a> 应用于您的问题：

 类Numeric 
 def to_rad 
 self * Math :: PI / 180 
 end 
 def to_deg 
 self * 180 / Math :: PI 
 end 
 end 
 
包含Math 
 
 R = 6371.0 
 
道路点（φ1，λ1，θ，d）
φ2= asin（sin（φ1）* cos（d / R）+ cos （sin（θ）* sin（d / R）* cos（φ1），cos（d / R）-sin（d / R）* cos（θ） （φ1）* sin（φ2））
λ2=（λ2+ 3 * Math :: PI）％（2 * Math :: PI） -  Math :: PI＃ o -180 .. + 180°
 [φ2，λ2] 
 end 
 
φ1，λ1= -33.to_rad，-71.6.to_rad＃Valparaíso
φ2 ，λ2= 31.4.to_rad，121.8.to_rad＃Shanghai 
 
d = R * acos（sin（φ1）* sin（φ2）+ cos（φ1）* cos（φ2）* cos（λ2 - λ1 ））
θ= atan2（sin（λ2 - λ1）* cos（φ2），cos（φ1）* sin（φ2） -  sin（φ1）* cos（φ2）* cos（λ2 - λ1））
 
航点=（0..d）.step（2000）.map {| d |航点（φ1，λ1，θ，d）} 
 
标记= waypoints.map {|φ，λ| ＃{φ.to_deg}，＃{λ.to_deg}} .join（|）
 
 putshttp://maps.googleapis.com/maps/api/staticmap?size = 640x320& sensor = false& markers =＃{markers}
  

生成Google Static Maps链接每隔2000公里从瓦尔帕莱索到上海的航点：

  http://maps.googleapis.com/maps/api/staticmap？大小= 640X320&安培;传感器=假安培;标记= -33.0，-71.60000000000002 | -32.54414813683714，-93.02142653011552 | -28.59922979115139，-113.43958859125276 | -21.877555679819015，-131.91586675556778 | -13.305784544363858，-148.5297601858932 | -3.7370081151180683，-163.94988578467394 | 6.094273692291354，-179.03345538133888 | 15.493534924596633,165.33401731030006 | 23.70233917422386,148.3186618914762 | 29.83806632244171,129.34766276764626 
  

Background:

I'm working with transport routes and Google provides Route points far apart enough to create 'shapes'. These are the bus/train routes you see in Google Maps.

My Requirement:

Google's points are far enough to create straight lines. However I want a point every, say, 5 metres.

Problem:

So, say I have two points [lat,long]:

[-33.8824219918503,151.206686052582] and [-33.8815434600467,151.206556440037]

Given those two points I can calculate the distance between them. Say it's 1km for the sake of argument.

So we can imagine an imaginary straight line in between those two points.

How do I generate coordinates for that imaginary line for every, say, 5 metres?

解决方案

Destination point given distance and bearing from start point applied to your problem:

class Numeric
  def to_rad
    self * Math::PI / 180
  end
  def to_deg
    self * 180 / Math::PI
  end
end

include Math

R = 6371.0

def waypoint(φ1, λ1, θ, d)
  φ2 = asin( sin(φ1) * cos(d/R) + cos(φ1) * sin(d/R) * cos(θ) )
  λ2 = λ1 + atan2( sin(θ) * sin(d/R) * cos(φ1), cos(d/R) - sin(φ1) * sin(φ2) )
  λ2 = (λ2 + 3 * Math::PI) % (2 * Math::PI) - Math::PI # normalise to -180..+180°
  [φ2, λ2]
end

φ1, λ1 = -33.to_rad, -71.6.to_rad   # Valparaíso
φ2, λ2 = 31.4.to_rad, 121.8.to_rad  # Shanghai

d = R * acos( sin(φ1) * sin(φ2) + cos(φ1) * cos(φ2) * cos(λ2 - λ1) )
θ = atan2( sin(λ2 - λ1) * cos(φ2), cos(φ1) * sin(φ2) - sin(φ1) * cos(φ2) * cos(λ2 - λ1) )

waypoints = (0..d).step(2000).map { |d| waypoint(φ1, λ1, θ, d) }

markers = waypoints.map { |φ, λ| "#{φ.to_deg},#{λ.to_deg}" }.join("|")

puts "http://maps.googleapis.com/maps/api/staticmap?size=640x320&sensor=false&markers=#{markers}"

Generates a Google Static Maps link with the waypoints from Valparaíso to Shanghai every 2,000 km:

http://maps.googleapis.com/maps/api/staticmap?size=640x320&sensor=false&markers=-33.0,-71.60000000000002|-32.54414813683714,-93.02142653011552|-28.59922979115139,-113.43958859125276|-21.877555679819015,-131.91586675556778|-13.305784544363858,-148.5297601858932|-3.7370081151180683,-163.94988578467394|6.094273692291354,-179.03345538133888|15.493534924596633,165.33401731030006|23.70233917422386,148.3186618914762|29.83806632244171,129.34766276764626

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