Question

当使用沿x轴的毫秒绘制gRaphael的线图时，我通常会在数据点的位置上出现不一致。最常见的是，初始数据点位于y轴的左侧（如下图所示），有时最后一个数据点将超出视图框的右侧/超过x轴的终止

有谁知道： 1）为什么会这样， 2）如何预防，＆amp; /或 3）如何检查它（如果我知道它何时发生/多少，我可以使用变换来移动线/点）。

我的代码：

var r = Raphael("holder"),
txtattr = { font: "12px sans-serif" };
var r2 = Raphael("holder2"),
txtattr2 = { font: "12px sans-serif" };

var x = [], y = [], y2 = [], y3 = [];

for (var i = 0; i < 1e6; i++) {
    x[i] = i * 10;
    y[i] = (y[i - 1] || 0) + (Math.random() * 7) - 3;
}
var demoX = [[1, 2, 3, 4, 5, 6, 7],[3.5, 4.5, 5.5, 6.5, 7, 8]];
var demoY = [[12, 32, 23, 15, 17, 27, 22], [10, 20, 30, 25, 15, 28]];

var xVals = [1288885800000, 1289929440000, 1290094500000, 1290439560000, 1300721700000,   1359499228000, 1359499308000, 1359499372000];
var yVals = [80, 76, 70, 74, 74, 78, 77, 72];
var xVals2 = [1288885800000, 1289929440000];
var yVals2 = [80, 76];

var lines = r.linechart(10, 10, 300, 220, xVals, yVals, { nostroke: false, axis: "0 0 1 1", symbol: "circle", smooth: true })
.hoverColumn(function () {
    this.tags = r.set();

    for (var i = 0, ii = this.y.length; i < ii; i++) {
        this.tags.push(r.tag(this.x, this.y[i], this.values[i], 160, 10).insertBefore(this).attr([{ fill: "#fff" }, { fill: this.symbols[i].attr("fill") }]));
        }
    }, function () {
        this.tags && this.tags.remove();
        });

lines.symbols.attr({ r: 3 });


var lines2 = r2.linechart(10, 10, 300, 220, xVals2, yVals2, { nostroke: false, axis: "0 0 1 1", symbol: "circle", smooth: true })
.hoverColumn(function () {
    this.tags = r2.set();

    for (var i = 0, ii = this.y.length; i < ii; i++) {
        this.tags.push(r.tag(this.x, this.y[i], this.values[i], 160, 10).insertBefore(this).attr([{ fill: "#fff" }, { fill: this.symbols[i].attr("fill") }]));
        }
    }, function () {
        this.tags && this.tags.remove();
        });

lines2.symbols.attr({ r: 3 });

我必须使用gRaphael，x轴必须以毫秒为单位（后面标有w /自定义日期字符串）

主要示例小提琴：http://jsfiddle.net/kcar/aNJxf/

次要示例小提琴（页面上的第4个示例经常显示两个轴错误）： http://jsfiddle.net/kcar/saBnT/

根本原因是snapEnds函数（第718行g.raphael.js），它所做的舍入虽然在某些情况下很好，但在其他情况下是从日期加上或减去年份。

在这一点之后没有完全一步，但由于数据点在每次舍入变得疯狂时都是错位的而不是在没有时，我会继续并假设这会导致计算问题图表列，也是在发送到snapEnds之前，值只是为了确认它不仅仅是接收错误计算的数据。

来自g.raphael.js的该函数的代码

snapEnds: function(from, to, steps) {
    var f = from,
        t = to;

    if (f == t) {
        return {from: f, to: t, power: 0};
    }

    function round(a) {
        return Math.abs(a - .5) < .25 ? ~~(a) + .5 : Math.round(a);
    }

    var d = (t - f) / steps,
        r = ~~(d),
        R = r,
        i = 0;

    if (r) {
        while (R) {
            i--;
            R = ~~(d * Math.pow(10, i)) / Math.pow(10, i);
        }

        i ++;
    } else {
        if(d == 0 || !isFinite(d)) {
            i = 1;
        } else {
            while (!r) {
                i = i || 1;
                r = ~~(d * Math.pow(10, i)) / Math.pow(10, i);
                i++;
            }
        }

        i && i--;
    }

    t = round(to * Math.pow(10, i)) / Math.pow(10, i);

    if (t < to) {
        t = round((to + .5) * Math.pow(10, i)) / Math.pow(10, i);
    }

    f = round((from - (i > 0 ? 0 : .5)) * Math.pow(10, i)) / Math.pow(10, i);
    return { from: f, to: t, power: i };
},

Answer 1

从snapEnds中移除了舍入废话并且没有更多问题，没有发现任何轴或图表的任何其他区域的任何缺点。如果你看到一个我喜欢听的话。

现在来自g.raphael.js的该函数的代码：

snapEnds: function(from, to, steps) {
     return {from: from, to: to, power: 0};       
},

Answer 2

您好评论如下：

        if (valuesy[i].length > width - 2 * gutter) {
            valuesy[i] = shrink(valuesy[i], width - 2 * gutter);
            len = width - 2 * gutter;
        }

        if (valuesx[i] && valuesx[i].length > width - 2 * gutter) {
            valuesx[i] = shrink(valuesx[i], width - 2 * gutter);
        }

在g.line.js中，似乎解决了这个问题，它也解决了y轴上的值的类似问题。

Answer 3

从v0.50升级到v0.51为我解决了这个问题。

Answer 4

仍然不确定为什么会发生这种情况，添加一个透明的集合并不是一个理想的选择。检查数据点是否在图形外部呈现的最简单方法似乎是获取轴集的边界框和数据点的边界框，并检查x和x2值之间的差异。

如果有人可以帮助我缩放数据点集，或者弄清楚如何使这一点不发生，我仍然会高兴地欣赏/投票答案

//assuming datapoints  is the Raphael Set for the datapoints, axes is the 
//Raphael Set for the axis, and datalines is the Raphael Set for the 
//datapoint lines
var pointsBBox = datapoints.getBBox();
var axesBBox = axes.getBBox();
var xGapLeft = Math.ceil(axesBBox.x - pointsBBox.x); 
//rounding up to integer to simplify, and the extra boost from y-axis doesn't 
//hurt, <1 is a negligible distance in transform
var xGapRight = Math.ceil(axesBBox.x2 - pointsBBox.x2);
var xGap = 0;
if(xGapLeft > 0){
     datapoints.transform('t' +xGapLeft +',0');
     datalines.transform('t' +xGapLeft +',0');
     xGap = xGapLeft;
}else if (xGapRight < 0) { //using else if because if it is a scale issue it will
//be too far right & too far left, meaning both are true and using transform will
//just shift it right then left and you are worse off than before, using 
//set.transform(scale) works great on dataline but when using on datapoints scales
// symbol radius not placement
     if (xGapLeft < 0 && xGapRight < xGapLeft) { xGapRight = xGapLeft; }  
//in this case the initial point is right of y-axis, the end point is right of 
//x-axis termination, and the difference between last point/axis is greater than
//difference between first point/axis

     datapoints.transform('t' +xGapRight +',0');
     datalines.transform('t' +xGapRight +',0');
     xGap = xGapRight;
}
rehookHoverOverEvent(xGap);  //there are so many ways to do this just leaving it
//here as a call to do so, if you don't the hover tags will be over the original 
//datapoints instead of the new location, at least they were in my case.

gRaphael折线图绘制超出轴的值

4 个答案: