Quick Start: Use Go language functions to implement simple data visualization map display

Quick Start: Use Go language functions to implement simple data visualization map display

With the development of the Internet, the importance of data is increasingly valued by people. Data visualization is to display complex data in a visual form, allowing people to understand the data more intuitively and clearly. In this article, we will use Go language functions to implement a simple data visualization map display function.

First of all, we need to install the related development environment of Go language. Please ensure that the Go language compiler and related libraries have been installed correctly.

First, we need to get the map data. In this example, we will use a file named map_data.txt, which contains the latitude and longitude information of each city. The sample data is as follows:

北京, 116.40, 39.90
上海, 121.47, 31.23
广州, 113.27, 23.13
深圳, 114.07, 22.62

We need to write a function to read this data and convert it into a data structure in the Go language. The following is a sample code:

package main

import (
    "fmt"
    "os"
    "strings"
)

type City struct {
    Name string
    Lat  float64
    Lng  float64
}

func ReadMapData(filename string) ([]City, error) {
    file, err := os.Open(filename)
    if err != nil {
        return nil, err
    }
    defer file.Close()

    var cities []City
    var line string
    for {
        _, err := fmt.Fscanf(file, "%s, %f, %f
", &line)
        if err != nil {
            break
        }

        data := strings.Split(line, ", ")
        if len(data) != 3 {
            continue
        }

        city := City{
            Name: data[0],
            Lat:  data[1],
            Lng:  data[2],
        }

        cities = append(cities, city)
    }

    return cities, nil
}

func main() {
    cities, err := ReadMapData("map_data.txt")
    if err != nil {
        fmt.Println("Error:", err)
        return
    }

    fmt.Println(cities)
}

In the above code, we first define the City structure to store the name, latitude and longitude information of the city. Then, we defined the ReadMapData function to read the map data file and convert it into slices of City. In the ReadMapData function, we use the Open function in the os package to open the file and then read the data line by line. We use the Fscanf function in the fmt package to parse the data in the file and store it into the corresponding City structure.

Next, we can call the ReadMapData function in the main function and print out the read data. In this example, we simply print out the data so we can check that the read results are correct.

After running the program, we will see the city information read from the map data file printed out.

Next, we need to display the locations of these cities on the map. In the Go language, we can use the go-echarts open source library to generate visual charts. The following is the sample code:

package main

import (
    "fmt"
    "github.com/go-echarts/go-echarts/charts"
    "os"
    "strings"
)

type City struct {
    Name string
    Lat  float64
    Lng  float64
}

func ReadMapData(filename string) ([]City, error) {
    // ...

func main() {
    cities, err := ReadMapData("map_data.txt")
    // ...

    // Create a new map chart
    mapChart := charts.NewMap("中国地图")
    mapChart.Add("城市", cities)

    // Set chart options
    mapChart.SetGlobalOptions(charts.TitleOpts{Title: "中国地图"})

    // Save chart as HTML file
    file, err := os.Create("map.html")
    if err != nil {
        fmt.Println("Error:", err)
        return
    }
    defer file.Close()

    mapChart.Render(file)
}

In the above code, we first imported the github.com/go-echarts/go-echarts/charts package, which is go- A sub-package provided by the echarts library, which contains functions for generating maps. Then, we created a new map chart mapChart. Next, we call the Add method to add the city's data to the map.

Then, we use the SetGlobalOptions method to set some chart options, such as the title. Finally, we call the Render method to save the map chart as an HTML file.

After running the program, we will see that the generated map.html file contains a simple map of China, and the locations of various cities are identified on the map.

Through this simple example, we can see the process of using Go language functions to realize data visualization map display. Of course, this is just an introductory example, and more complex data and chart styles may need to be processed in actual applications. But this example can help us better understand the application of Go language functions in data visualization map display. Hope this article helps you!

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