Question

我的图形按照我想要的方式工作-除了一部分... X轴。尽管它显示正确的值，但我只需要将其格式化为“ M / D / Y，时间”格式并渲染每个。目前，它仅每6小时显示一次滴答声。我拥有所有数据（在控制台中是'DTIME #########'）。

我需要做的就是正确格式化x轴日期，并实际渲染控制台中的所有日期。

谢谢！

这是文件的所有代码：

class Linechart extends React.Component {
constructor(props) {
    super(props);

    this.draw_chart = this.draw_chart.bind(this);

    this.state = {}     
}

componentDidMount() {
    setTimeout(() => {

        // EARTHQUAKES FROM FETCH FROM FEED.JSX
        var parsed_quakes = (store.getState()).quake_data[0];

        // MAGNITUDE 3 QUAKES
        const mag_three = parsed_quakes.filter(quake => 
            quake.properties.mag >= 3 && quake.properties.mag < 4
        );

        // DYNAMIC FUNCTION TO PARSE QUAKES
        const mag_parse = (quakemag) => {
            // NEW OBJECT
            var mag_three_obj = new Object();
            const quake_arr = []; // STORE QUAKES OBJECTS

            var line_points = [];

            for (var i = 0; i < quakemag.length; i++) {

                // GET DATE AND TIME OF EACH MAG 3 EARTHQUAKE
                const time_stamp  = new Date(quakemag[i].properties.time);
                const string_time = time_stamp.toString();
                const mag_three_time  = new Date(string_time.split(' ').slice(1, 5)).toLocaleString();

                // DAY/TIME
                const quake_three_time = mag_three_time.split(' ');

                // MAGNITUDE
                const quake_three_mag = quakemag[i].properties.mag;             

                mag_three_obj = {
                    emag:  quake_three_mag,
                    etime: quake_three_time
                }

                var date_format  = new Date(mag_three_time);
                var milli_format = date_format.getTime();

                line_points.push([quake_three_mag, milli_format]);

                quake_arr.push(mag_three_obj);


            } // END LOOP 

            // console.log('QUAKE ARR ', quake_arr);
            // console.log('LINE POINTS ', line_points);

            // DISPATCH TO USE IN draw_chart FUNCTION
            store.dispatch({ type: 'PARSED-QUAKES', payload: quake_arr });
            return quake_arr;

        } // END MAG PARSE FUNCTION

        // PARSED MAGNITUDE THREE INVOCATION
        const parsed_mag_three = mag_parse(mag_three);      

        this.draw_chart(parsed_mag_three);

    }, 1000);           
}

// LINE CHART FUNCTION
draw_chart(data) {

    // DECLARE MARGIN AND DIMENSIONS
    var margin = {
        top: 20,
        right: 20,
        bottom: 80,
        left: 80
    }

    var width  = 1100 - margin.left - margin.right;
    var height = 500 - margin.top - margin.bottom;

    // APPEND THE SVG OJECT TO THE BODY OF THE PAGE
    // APPEND A GROUP ELEMENT AND MOVE IT TO TOP LEFT 
    var svg = d3.select('.line-graph').append('svg')
        .attr("width", width + margin.left + margin.right)
        .attr("height", height + margin.top + margin.bottom)
        .append("g")
            .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

        // GET PARSED EARTHQUAKES FROM REDUX STORE
        let parsed_quakes = (store.getState()).quake_data[0];                       

        parsed_quakes.forEach((data) => {               
            data.etime = data.etime.join(' ');
            data.emag  = data.emag;
        });

        // DEFINE THE LINE
        var value_line = d3.line()
            .x(function(d) {return x(d.etime);})
            .y(function(d) {return y(d.emag);})

        // SET THE RANGES
        var x = d3.scaleTime().range([0, width]);
        var y = d3.scaleLinear().range([height, 3]);

        // CONVERT DATES BACK TO MILLISECONDS
        data.forEach(function(el) {
            var date_format  = new Date(el.etime);
            var millis_format = date_format.getTime();

            // CONVERT THE STRING DATE/TIME FORMAT TO MILLISECONDS
            el.etime = millis_format;               
        })          

        console.log('DATA ARRAY 1ST EL ', data[0]);
        console.log('DATA ARRAY LAST EL ', data[data.length - 1]);

        // SET THE DOMAINS
        // CREATE VALUES FOR THE X AXIS FROM MIN TO MAX 
        x.domain(
            d3.extent(data, function(d) {                   
                console.log('DTIME ', d.etime);                 
                d.etime = new Date(d.etime);
                return d.etime; 
            })
        );  

        // CREATE VALUES FOR THE Y AXIS FROM MIN TO MAX 
        y.domain([3, d3.max(data, function(d) { return d.emag })]);

        svg.append('path')
            .data([data])
            .attr('class', 'line')
            .attr('d', value_line)

        // APPEND X AXIS
        svg.append('g')
            .call(d3.axisBottom(x))
            .attr('transform', 'translate(0,' + height + ')')
            .append('text')
            .attr('fill', '#E1ECA5')                
            .attr('x', 6)
            .attr('dx', '1.5em')
            .attr('dy', '2.5em')
            .attr('text-anchor', 'end')
            .attr("font-size", 16)
            .text('Time');

        // APPEND THE Y AXIS
        svg.append('g')             
            .call(d3.axisLeft(y))
            .append("text")
            .attr("fill", "#E1ECA5")
            .attr("transform", "rotate(-90)")
            .attr("y", 0)
            .attr("dy", "-2.5em")
            .attr("text-anchor", "end")
            .attr("font-size", 16)
            .text("Magnitude");

}

render() {      
    return (
        <div className='line-graph'>

        </div>
    )
}}

Answer 1

创建轴以使用以下两种方法时：

格式化日期
指定刻度频率

这看起来像：

var axis = d3.axisBottom(x) 
  .ticks(d3.timeDay.every(1))           // a tick for every day.
  .tickFormat(d3.timeFormat("%d/%m/%y"));  // date in format: 31/01/19

这会给您类似的东西（日期格式不同）

var parseTime = d3.timeParse("%B %d, %Y");

var min = parseTime("January 1, 2019");
var max = parseTime("January 31, 2019");
var mid = parseTime("January 16, 2019");


var x = d3.scaleTime()
  .domain([min,max])
  .range([20,480])


var axis = d3.axisBottom(x)
  .ticks(d3.timeDay.every(1))
  .tickFormat(d3.timeFormat("%d-%B"));
  
var g = d3.select("svg")
  .append("g")
  .attr("transform","translate(0,50)")
  .call(axis);
  
g.selectAll("text")
  .attr("transform","translate(10,0)rotate(60)")
  .style("text-anchor","start");

// Animate a demonstration:
var i = 0;
function cycle() {
  x.domain([[min,mid,min,min][i%4],[mid,max][i%2]]);
  
  g.transition()
    .duration(2000)
    .call(axis)
    .on("end", function() {
      if(i++ < 40) cycle(); 
   })
}

cycle();

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/5.7.0/d3.min.js"></script>
<svg width="500" height="300"></svg>

有关格式规范的完整列表，请参见文档here。

我的X轴未呈现我想要的所有刻度线-D3 JS

1 个答案: