如何使用 d3.js 将图形/数据添加到人力车？

Question

这是我所拥有的：

http://jsfiddle.net/bozdoz/Q6A3L/

背景栏代码：

maxData = 80000000;
maxHeight = 250;
var yScale = d3.scale.linear().
  domain([0, maxData]). // your data minimum and maximum
  range([0, maxHeight]); // the pixels to map to, e.g., the height of the diagram.

var riskpoints = [62000000,48000000,30000000];
var rectDemo = d3.select("#chart").
    append("svg:svg").
    attr("width", 400).
    attr("height", maxHeight).
    attr('class','risk');

rectDemo.append("svg:rect").
    attr("x",0).
    attr("y", maxHeight - yScale(riskpoints[0])).
    attr("height", yScale(riskpoints[0]) - yScale(riskpoints[1])).
    attr("width", '100%').
    attr("fill", "rgba(0,100,0,.3)");

rectDemo.append("svg:rect").
    attr("x",0).
    attr("y", maxHeight - yScale(riskpoints[1])).
    attr("height", yScale(riskpoints[1]) - yScale(riskpoints[2])).
    attr("width", '100%').
    attr("fill", "rgba(100,100,0,.3)");

rectDemo.append("svg:rect").
    attr("x",0).
    attr("y", maxHeight - yScale(riskpoints[2])).
    attr("height", yScale(riskpoints[2])).
    attr("width", '100%').
    attr("fill", "rgba(100,0,0,.3)");

这正是我想要的，除了我已将红色、黄色、绿色背景条设置为固定高度。

当您使用滑块时，或者更重要的是，当重新生成图表时（它将使用实际数据），我希望背景条调整到正确的高度。

例如，在图像中，绿条介于 300M 和 200M 之间。如果删除除红色（垂直）条之外的所有图形数据，绿色条（水平）刚好在 40M 以上。这是因为背景条的位置/高度不会重新生成，而图形数据的位置/高度是通过人力车javascript重新生成的。

如何将这些数据放入人力车图中以便重新生成？

Answer 1

解决方案是设置更新函数来计算背景条的新高度， 要获得显示的条形图，您可以使用 graph.series.active();您也可能希望将 vars 保持在同一范围内....

所以解决方案本身：

var maxHeight;
var background_update = function(graph) {
    //skip 1st time;
    if (maxHeight === undefined) {return;}
    var series=graph.series.active();
    maxHeight=yScale(get_maximum_all(series));
    //console.log(maxHeight);
    var red_riskpoint=get_maximum("y",series[0]);
    var yellow_riskpoint=get_maximum("y",series[1]);
    var green_riskpoint=get_maximum("y",series[2]);
    //console.log(graph.series.active());
    console.log(yScale(red_riskpoint),yScale(yellow_riskpoint),yScale(green_riskpoint));
    
   // return;
    
    b_red.attr("y", maxHeight - yScale(red_riskpoint)).attr("height", yScale(red_riskpoint));
    b_yellow.attr("y", maxHeight - yScale(yellow_riskpoint)).attr("height", Math.abs(yScale(yellow_riskpoint) - yScale(red_riskpoint)));
    b_green.attr("y", maxHeight - yScale(green_riskpoint)).attr("height", Math.abs(yScale(green_riskpoint) - yScale(yellow_riskpoint)));
    console.log(maxHeight-yScale(green_riskpoint));
};
var get_maximum_all=function(series) {
    var max=0;
    for (var i in series) {
        var stack=series[i].stack;
        for (n in stack) {
            if (stack[n].y>max) {max=stack[n].y;}
            if (stack[n].y0>max) {max=stack[n].y0;}
        }
    }
    return max;
}
    var get_maximum=function(tag,object){
    var max=0;
    for (var i in object.stack) {
        if (object.stack[i][tag]>max) {max=object.stack[i][tag];}
    }
return max;
    }
Rickshaw.Graph.RangeSlider = function(args) {

    var element = this.element = args.element;
    var graph = this.graph = args.graph;


    $(element).slider({

        range: true,
        min: graph.dataDomain()[0],
        max: graph.dataDomain()[1],
        values: [
            graph.dataDomain()[0],
            graph.dataDomain()[1]
            ],
        slide: function(event, ui) {

            graph.window.xMin = ui.values[0];
            graph.window.xMax = ui.values[1];
            graph.update();

            // if we're at an extreme, stick there
            if (graph.dataDomain()[0] == ui.values[0]) {
                graph.window.xMin = undefined;
            }
            if (graph.dataDomain()[1] == ui.values[1]) {
                graph.window.xMax = undefined;
            }
        }
    });


    element.style.width = graph.width + 'px';

    graph.onUpdate(function() {

        var values = $(element).slider('option', 'values');

        $(element).slider('option', 'min', graph.dataDomain()[0]);
        $(element).slider('option', 'max', graph.dataDomain()[1]);

        if (graph.window.xMin == undefined) {
            values[0] = graph.dataDomain()[0];
        }
        if (graph.window.xMax == undefined) {
            values[1] = graph.dataDomain()[1];
        }

        $(element).slider('option', 'values', values);
        background_update(graph);
    });
}

其他代码几乎和你摆弄的一样，

我的小提琴here

请注意，我不确定如何计算风险点，我只是试图获得最大值。我相信你可以通过查看console.log(series)来进行风险点计算

b_red,b_green,b_yellow 是 d3 个初始化背景条的选择。

Answer 2

在@eicto 的回答的帮助下，我找到了一些解决方案。

var maxHeight = 250;
var theSVG = d3.select("#chart svg");

//from @eicto: get the maximum value on the current chart
function get_maximum_all(series) { 
    var max=0;
    for (var i in series) {
        var stack=series[i].stack;
        for (n in stack) {
            if (stack[n].y>max) {max=stack[n].y;}
            if (stack[n].y0>max) {max=stack[n].y0;}
        }
    }
    return parseInt(max);
}

//create a function to call on graph update event
function createRiskPoints(riskpoints){
//these variables need to change on each graph update
   var series = graph.series.active();
//this variable should be get_max_y_axis, but I don't know how to do that
   var maxData = get_maximum_all(series);
   var yScale = d3.scale.linear().
  domain([0, maxData]).
  range([0, maxHeight]);

//using dummy values for now
   var riskpoints = (riskpoints) ? riskpoints : [300000000,200000000,100000000];

//insert the bars so they go behind the data values
theSVG.insert("svg:rect", ":first-child").
    attr("x",0).
    attr("y", maxHeight - yScale(riskpoints[0])).
    attr("height", yScale(riskpoints[0]) - yScale(riskpoints[1])).
    attr("width", '100%').
    attr("fill", "rgba(0,100,0,.2)");

theSVG.insert("svg:rect", ":first-child").
    attr("x",0).
    attr("y", maxHeight - yScale(riskpoints[1])).
    attr("height", yScale(riskpoints[1]) - yScale(riskpoints[2])).
    attr("width", '100%').
    attr("fill", "rgba(100,100,0,.2)");

theSVG.insert("svg:rect", ":first-child").
    attr("x",0).
    attr("y", maxHeight - yScale(riskpoints[2])).
    attr("height", yScale(riskpoints[2])).
    attr("width", '100%').
    attr("fill", "rgba(100,0,0,.2)");
}
//call the function
   createRiskPoints();
//call the function on graph update: thanks to @eicto
   graph.onUpdate( createRiskPoints );​

现在条形图会随着图表的变化而变化；但是，它们不是按比例缩放的。这将是我的下一个任务。

http://jsfiddle.net/bozdoz/Q6A3L/