d3中的钢筋位置与轴不匹配 [英] Bar position in d3 is not matching with axis

问题描述

我有一个使用d3js制作的条形图，其中我无法沿x轴正确放置这些条形.条形相对于轴抽线的位置不正确.

I've a bar chart made using d3js where I'm unable to position the bars properly along the x-axis. The bars are not positioned relative to the axis tics.

以下是同一段代码.

var width = 216;
var height = 200;
var barPadding = 18;
var barWidth = 58;
var dataSize = d3.selectAll(dataset).size();
var margin = { top: 10, right: 0, bottom: 58, left: 30 };
var width_box_sizing_border_box = width + margin.left + margin.right;
var height_box_sizing_border_box = height + margin.bottom + margin.top;
//var start = (width - margin.left - margin.right - (dataSize * barWidth) + barPadding) / 2;

var graph;
var xScale;
var yScale;
var dataset;

var xTicks = 6;
var yTicks = 6;

dataset = [{ desc: 'test1', val: 40 }, { desc: 'some dummy text here', val: 120 }];

xScale = d3.scaleBand()
    .domain(dataset.map(function (d) {
        return d.desc;
    }))
    .range([margin.left, width-margin.right]);

yScale = d3.scaleLinear()
    .range([height, 0])
    .domain([0, 350]);

graph = d3.select("#graph")
    .append("svg")
    .attr("class", "bar-chart")
    .attr("width", width_box_sizing_border_box)
    .attr("height", height_box_sizing_border_box)

graph.append("g")
    .attr("class", "x-scale")
    .attr("transform", "translate(0," + (height + margin.top) + ")")
    .call(d3.axisBottom(xScale).ticks(xTicks))
    .selectAll(".tick text")
    .call(wrap, xScale.bandwidth());

graph.append("g")
    .attr("class", "y-scale")
    .attr("transform", "translate(" + margin.left + "," + margin.top + ")")
    .call(d3.axisLeft(yScale).ticks(yTicks).tickPadding(10));

graph
    .append("g")
    .attr("transform", "translate(0," + margin.top + ")")
    .attr('class', 'graph-placeholder')
    .selectAll("rect")
    .data(dataset)
    .enter()
    .append("rect")
    .attr("class", "bar1")
    .attr("height", height)
    .attr("width", barWidth - barPadding)
    .attr('x', d => xScale(d.desc));

graph
    .append("g")
    .attr("transform", "translate(0," + margin.top + ")")
    .attr('class', 'graph-main')
    .selectAll("bar1")
    .data(dataset)
    .enter()
    .append("rect")
    .attr("class", "bar2")
    .attr('x', d => xScale(d.desc))
    .attr("y", function (d) {
        return yScale(d.val);
    })
    .attr("height", function (d) {
        return height - yScale(d.val);
    })
    .attr("width", barWidth - barPadding);


graph
    .append("g")
    .attr("transform", "translate(0," + margin.top + ")")
    .attr('class', 'bar-label')
    .selectAll("text")
    .data(dataset)
    .enter()
    .append("text")
    .text(d => d.val + '%')
    .attr('x', d => xScale(d.desc))
    .attr("y", function (d) {
        return yScale(d.val) - 5;
    })

function wrap(text, width) {
    text.each(function () {
        var text = d3.select(this),
            words = text.text().split(/\s+/).reverse(),
            word,
            line = [],
            lineNumber = 0,
            lineHeight = 1,
            y = text.attr("y"),
            dy = parseFloat(text.attr("dy")),
            tspan = text.text(null).append("tspan").attr("x", 0).attr("y", y).attr("dy", dy + "em");
        while (word = words.pop()) {
            line.push(word);
            tspan.text(line.join(" "));
            if (tspan.node().getComputedTextLength() > width) {
                line.pop();
                tspan.text(line.join(" "));
                line = [word];
                tspan = text.append("tspan").attr("x", 0).attr("y", y).attr("dy", ++lineNumber * lineHeight + dy + "em").text(word);
            }
        }
    });
}

.bar-chart {
  background-color: #ccc;
}

.bar2 {
  fill: steelblue;
}

.bar1 {
  fill: #f2f2f2;
}

text {
  font-size: 12px;
  text-anchor: middle;
}

.bar-label text {
  text-anchor: start;
}
path.domain {
  stroke-width: 0;
  display: none;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/5.7.0/d3.min.js"></script>
<div class="container">
  <div id="graph"></div>
</div>

推荐答案

以下是计算中心点以放置条形/文本的方法

Here's how you can compute the center point to place the bars/texts

条形文字: xScale.bandwidth()/2 - barWidth/2

文本的其他偏移量，以使文本在条中居中: 分配了text属性后，请根据barWidth和此特定的文本宽度放置文本(即x).

Additional offset for the texts to center them within the bars: Once the text attribute is assigned, position the text (i.e. x) based on the barWidth and this particular text width.

简而言之:barWidth/2 - textWidth/2，为此，您可以使用 getBBox 方法.方法如下:

In short terms: barWidth/2 - textWidth/2 and to do that you can use the getBBox method. Here's how:

.attr('x', function (d) {
    return xScale(d.desc) + ((barWidth - barPadding)/2 - d3.select(this).node().getBBox().width/2);
});

将以上2项更改应用于图表，这是您的小提琴(和内联代码段)的一个分支

Applying the above 2 changes to your chart, here's a fork of your fiddle (and an inline snippet)

var width = 216;
var height = 200;
var barPadding = 18;
var barWidth = 58;
var dataSize = d3.selectAll(dataset).size();
var margin = { top: 10, right: 0, bottom: 58, left: 30 };
var width_box_sizing_border_box = width + margin.left + margin.right;
var height_box_sizing_border_box = height + margin.bottom + margin.top;
//var start = (width - margin.left - margin.right - (dataSize * barWidth) + barPadding) / 2;

var graph;
var xScale;
var yScale;
var dataset;

var xTicks = 6;
var yTicks = 6;

dataset = [{ desc: 'test1', val: 40 }, { desc: 'some dummy text here', val: 120 }];

xScale = d3.scaleBand()
    .domain(dataset.map(function (d) {
        return d.desc;
    }))
    .range([margin.left, width-margin.right]);

yScale = d3.scaleLinear()
    .range([height, 0])
    .domain([0, 350]);

graph = d3.select("#graph")
    .append("svg")
    .attr("class", "bar-chart")
    .attr("width", width_box_sizing_border_box)
    .attr("height", height_box_sizing_border_box)

graph.append("g")
    .attr("class", "x-scale")
    .attr("transform", "translate(0," + (height + margin.top) + ")")
    .call(d3.axisBottom(xScale).ticks(xTicks))
    .selectAll(".tick text")
    .call(wrap, xScale.bandwidth());

graph.append("g")
    .attr("class", "y-scale")
    .attr("transform", "translate(" + margin.left + "," + margin.top + ")")
    .call(d3.axisLeft(yScale).ticks(yTicks).tickPadding(10));

graph
    .append("g")
    .attr("transform", "translate(" + (xScale.bandwidth()/2 - (barWidth - barPadding)/2) + "," + margin.top + ")")
    .attr('class', 'graph-placeholder')
    .selectAll("rect")
    .data(dataset)
    .enter()
    .append("rect")
    .attr("class", "bar1")
    .attr("height", height)
    .attr("width", barWidth - barPadding)
    .attr('x', d => xScale(d.desc));

graph
    .append("g")
    .attr("transform", "translate(" + (xScale.bandwidth()/2 - (barWidth - barPadding)/2) + "," + margin.top + ")")
    .attr('class', 'graph-main')
    .selectAll("bar1")
    .data(dataset)
    .enter()
    .append("rect")
    .attr("class", "bar2")
    .attr('x', d => xScale(d.desc))
    .attr("y", function (d) {
        return yScale(d.val);
    })
    .attr("height", function (d) {
        return height - yScale(d.val);
    })
    .attr("width", barWidth - barPadding);


graph
    .append("g")
    .attr("transform", "translate(" + (xScale.bandwidth()/2 - (barWidth - barPadding)/2) + "," + margin.top + ")")
    .attr('class', 'bar-label')
    .selectAll("text")
    .data(dataset)
    .enter()
    .append("text")
    .text(d => d.val + '%')
    .attr("y", function (d) {
        return yScale(d.val) - 5;
    }).attr('x', function (d) {
    	return xScale(d.desc) + ((barWidth - barPadding)/2 - d3.select(this).node().getBBox().width/2);
    });

function wrap(text, width) {
    text.each(function () {
        var text = d3.select(this),
            words = text.text().split(/\s+/).reverse(),
            word,
            line = [],
            lineNumber = 0,
            lineHeight = 1,
            y = text.attr("y"),
            dy = parseFloat(text.attr("dy")),
            tspan = text.text(null).append("tspan").attr("x", 0).attr("y", y).attr("dy", dy + "em");
        while (word = words.pop()) {
            line.push(word);
            tspan.text(line.join(" "));
            if (tspan.node().getComputedTextLength() > width) {
                line.pop();
                tspan.text(line.join(" "));
                line = [word];
                tspan = text.append("tspan").attr("x", 0).attr("y", y).attr("dy", ++lineNumber * lineHeight + dy + "em").text(word);
            }
        }
    });
}

.bar-chart {
  background-color: #ccc;
}

.bar2 {
  fill: steelblue;
}

.bar1 {
  fill: #f2f2f2;
}

text {
  font-size: 12px;
  text-anchor: middle;
}

.bar-label text {
  text-anchor: start;
}
path.domain {
  stroke-width: 0;
  display: none;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/5.7.0/d3.min.js"></script>
<div class="container">
  <div id="graph"></div>
</div>

小提琴链接: http://jsfiddle.net/xsuL8q4j/

希望这会有所帮助.

这篇关于d3中的钢筋位置与轴不匹配的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！