Question

我想解析一个GeoJSON文件（Point类型）并将坐标（lat / lng）保存到.CSV文件。如何用Ruby做到这一点？以下是GeoJSON文件。提前谢谢！

{  "type": "FeatureCollection",  
    "features": [
{ "type": "Feature",
  "id": 1,
  "properties": {
    "cluster": {
      "x": -0.229559,
      "y": 0.270089
    }
  },
  "geometry": {
    "type": "Point",
    "coordinates": [
      -74.1518294,
      40.5793043
    ]
  }
},
{
  "type": "Feature",
  "id": 2,
  "properties": {
    "cluster": {
      "x": 0.00379515,
      "y": 0.121912
    }
  },
  "geometry": {
    "type": "Point",
    "coordinates": [
      -74.0818064,
      40.9278118
    ]
  }
}, ]}

Answer 1

您可以使用rgeo-geojson gem来执行此操作：

require 'rgeo/geo_json'
require 'csv'

points = RGeo::GeoJSON.decode(json, json_parser: :json) # json must be a string here

CSV.open("points.csv", "w") do |csv|
  csv << ["x", "y"]
  points.each do |point|
    csv << [point.geometry.x, point.geometry.y]
  end
end

Answer 2

如果您只想在csv文件中存储lat和lng，

$ cat geo.json 
{  "type": "FeatureCollection",
    "features": [
{ 
  "type": "Feature",
  "id": 1,
  "properties": {
    "cluster": {
      "x": -0.229559,
      "y": 0.270089
    }
  },
  "geometry": {
    "type": "Point",
    "coordinates": [
      -74.1518294,
      40.5793043
    ]
  }
},
{
  "type": "Feature",
  "id": 2,
  "properties": {
    "cluster": {
      "x": 0.00379515,
      "y": 0.121912
    }
  },
  "geometry": {
    "type": "Point",
    "coordinates": [
      -74.0818064,
      40.9278118
    ]
  }
}  
]
  }

ruby脚本

require 'json'
require 'csv'

q = h['features'].map {|e| e['geometry']['coordinates'] }
#=> [[-74.1518294, 40.5793043], [-74.0818064, 40.9278118]]
CSV.open('coords.csv', 'wb') {|csv| q.each {|e|csv << e }}

csv文件的内容。

$ cat coords.csv 
-74.1518294,40.5793043
-74.0818064,40.9278118

如果您还想存储ID，请更改

q = h["features"].map {|e| [e['id'], e['geometry']['coordinates']].flatten }

如果你想写标题，

CSV.open('coords.csv', "wb") do |csv|
  csv << ['ID', 'LAT', 'LNG']
  q.each {|e|csv << e }
end

coords的内容

$ cat coords.csv 
ID,LAT,LNG
1,-74.1518294,40.5793043
2,-74.0818064,40.9278118

如何用Ruby解析GeoJSON并将坐标保存到.csv文件？

2 个答案: