问题描述
我想在 R 中制作一张地图，根据数据集（在我的例子中，鲨鱼物种的长度数据）为粮农组织渔区着色。
我更喜欢在 ggplot 中制作等值线图，但其他类型的地图也可以。最坏的情况是我可以添加气泡的粮农组织区域底图。即使只是现有的粮农组织区域底图也会很棒。欢迎提出任何建议！
解决方法
我转到 this page 并点击找到 this link 以检索 GeoJSON 文件：
2021-07-26 17:50:50.679871-0400 newFitnessApp[510:22218] [Assert] View <(null):0x0> does not conform to UITextInput protocol
2021-07-26 17:50:50.679947-0400 newFitnessApp[510:22218] [Assert] View <(null):0x0> does not conform to UITextInput protocol
2021-07-26 17:50:50.679972-0400 newFitnessApp[510:22218] [Assert] View <(null):0x0> does not conform to UITextInput protocol
2021-07-26 17:50:50.679990-0400 newFitnessApp[510:22218] [Assert] View <(null):0x0> does not conform to UITextInput protocol
2021-07-26 17:50:50.680006-0400 newFitnessApp[510:22218] [Assert] View <(null):0x0> does not conform to UITextInput protocol
2021-07-26 17:50:50.680120-0400 newFitnessApp[510:22218] [Assert] View <(null):0x0> does not conform to UITextInput protocol
2021-07-26 17:50:50.680146-0400 newFitnessApp[510:22218] [Assert] View <(null):0x0> does not conform to UITextInput protocol
2021-07-26 17:50:50.680165-0400 newFitnessApp[510:22218] [Assert] View <(null):0x0> does not conform to UITextInput protocol
2021-07-26 17:50:50.680182-0400 newFitnessApp[510:22218] [Assert] View <(null):0x0> does not conform to UITextInput protocol
2021-07-26 17:50:50.766468-0400 newFitnessApp[510:22218] [Snapshotting] Snapshotting a view (0x15268e680,_UIReplicantView) that has not been rendered at least once requires afterScreenUpdates:YES.
struct EditNotesView: View {
@Binding var notes: String
//@State private var notes: String = "type notes here"
@Binding var isShowingSheet: Bool
@EnvironmentObject var dataStore: DataStore
@Environment(\.colorScheme) var colorScheme
@ObservedObject var workoutDetailViewModel: WorkoutDetailViewModel
var body: some View {
VStack {
HStack {
Button("Cancel") {
isShowingSheet = false
}
.padding([.top,.leading])
.foregroundColor(Color.blue)
Spacer()
Button("Save") {
if let unwrappedHKWorkout = workoutDetailViewModel.fullyLoadedWorkout?.hkWorkout {
print("NOW WE WILL SAVE")
workoutDetailViewModel.updateMetadataAndSaveWorkout(workoutToBeUpdated: unwrappedHKWorkout,updateType: .notes(notes)) { (updatedWorkout) in
}
}
isShowingSheet = false
}
.padding([.top,.trailing])
.foregroundColor(Color.red)
}
HStack {
TextEditor(text: $notes)
.font(.body)
.if(notes == "type notes here") { $0.foregroundColor(Color.gray) } //This is a hack until TextEditor has a placeholder option
.padding()
//This is a hack until TextEditor has a placeholder option
.onTapGesture {
if notes == "type notes here" {
self.notes = ""
}
}
}
}
.onAppear {
if let unwrappedNotes = workoutDetailViewModel.fullyLoadedWorkout?.trackerMetadata.notes {
notes = unwrappedNotes
} else {
notes = "type notes here"
}
}
}
}
//This function is used so that TextEditor can take an optional string. If it gets updated in SwiftUI we can delete it
func ??<T>(lhs: Binding<Optional<T>>,rhs: T) -> Binding<T> {
Binding(
get: { lhs.wrappedValue ?? rhs },set: { lhs.wrappedValue = $0 }
)
}
从现在开始，我一直在关注 this example from the R graph gallery，并得到了 this SO question 和 these notes 的帮助：
download.file("http://www.fao.org/fishery/geoserver/fifao/ows?service=WFS&request=GetFeature&version=1.0.0&typeName=fifao:FAO_AREAS_CWP&outputFormat=json",dest="FAO.json")
此时，library(geojsonio)
library(sp)
library(broom)
library(ggplot2)
library(dplyr) ## for joining values to map
spdf <- geojson_read("FAO.json",what = "sp")
将显示区域的普通（base-R）图。
plot(spdf)
注释
- 有些步骤很慢，可能值得研究如何粗化/降低空间多边形对象的分辨率（如果您只想显示图片，分辨率级别可能会过大）
- 老实说，默认的连续配色方案可能更好，但现在所有酷孩子似乎都喜欢“viridis”，所以......
- 可能有更好的方法来完成这些工作（例如设置地图投影、为陆地填充背景颜色，......？）