gRaphael 折线图绘制轴以外的值

gRaphael linechart draws values beyond axis

本文关键字:折线图 绘制 gRaphael      更新时间:2023-09-26

当使用gRaphael沿x轴使用毫秒绘制折线图时,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(如下面的小提琴所示),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,和/或3)如何检查它(如果我知道何时发生/移动多少,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 });

我确实必须使用 gRaphael,并且 x 轴必须以毫秒为单位(稍后会标记带有自定义日期字符串)

主要例子小提琴: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),它所做的四舍五入,虽然在某些情况下很好,但在其他情况下是增加或减去日期的年份。

这一点之后还没有完全完成,但是由于每次舍入变得疯狂而不是不疯狂时数据点都会放错位置,因此我将继续假设这会导致计算图表列的问题,同样在发送到 snapEnds 之前,值是正确的只是为了确认它不仅仅是接收计算错误的数据。

来自 G.Raphael 的函数代码.js

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 };
},

从snapEnd中删除了舍入废话,没有更多的问题,没有注意到任何一个轴或图表的任何其他区域的任何缺点。 如果你看到一个,我很想听听。

来自 G.Raphael 的该函数的代码.js现在:

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

如果你评论这个:

        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,它似乎解决了这个问题,它也解决了y轴上的值的类似问题。

从 v0.50 升级到 v0.51 为我解决了这个问题。

仍然不确定为什么会发生这种情况,添加透明集不是一个理想的选择。检查数据点是否呈现在图形之外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扩展数据点集,或者弄清楚如何使这种情况根本不发生,我仍然会很高兴地欣赏/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.