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A speedometer-style chart for d3.
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| function gauge() { | |
| 'use strict'; | |
| var settings = { | |
| 'arc-size': 10, | |
| angle: 90.0, // Degrees | |
| arcGenerator: d3.svg.arc(), | |
| angleScale: d3.scale.linear().range([-45, 45]), // Value to degrees | |
| domain: null, // Raw values to that correspond to each color in range. | |
| margin: { | |
| bottom: 20, | |
| left: 20, | |
| right: 20, | |
| top: 20 | |
| }, | |
| range: null, // Colors to use behind each segment. | |
| transition: 500 | |
| }; | |
| function deg2Rad(degrees) { | |
| return degrees * Math.PI / 180; | |
| } | |
| function getterSetter(variable, onSet) { | |
| if (typeof onSet !== 'function') { | |
| onSet = function() {}; | |
| } | |
| return function(value) { | |
| if (typeof value === 'undefined') { | |
| return settings[variable]; | |
| } | |
| settings[variable] = value; | |
| onSet(value); | |
| return chart; | |
| }; | |
| } | |
| var chart = function(selection) { | |
| if (!settings.domain) { | |
| throw 'Cannot render a gauge without a domain.'; | |
| } | |
| if (!settings.range) { | |
| throw 'Cannot render a gauge without a range.'; | |
| } | |
| var content = selection.select('.content'); | |
| if (content.empty()) { | |
| content = selection.append('g') | |
| .classed('content', true) | |
| .attr('transform', 'translate(' + settings.margin.left + ',' + settings.margin.top + ')'); | |
| } | |
| content.transition(settings.transition) | |
| .attr('transform', 'translate(' + settings.margin.left + ',' + settings.margin.top + ')'); | |
| var datum = selection.datum(), | |
| node = selection.node(), | |
| boundingRect = node.getBoundingClientRect(), | |
| height = parseInt(boundingRect.height, 10) - settings.margin.bottom - settings.margin.top, | |
| width = parseInt(boundingRect.width, 10) - settings.margin.left - settings.margin.right, | |
| width_2 = width / 2, | |
| radius = Math.min(width_2 / Math.cos(deg2Rad(90.0 - (settings.angle / 2))), height); | |
| // Draw gauge arc. | |
| settings.arcGenerator.outerRadius(radius).innerRadius(radius - settings['arc-size']); | |
| var arc = content.select('.arc'); | |
| if (arc.empty()) { | |
| var arc = content.append('g') | |
| .classed('arc', true) | |
| .attr("transform", "translate(" + width_2 + "," + height + ")"); | |
| } | |
| var arcSegmentData = settings.range.map(function(d, i) { | |
| return { | |
| color: settings.range[i], | |
| endAngle: deg2Rad(settings.angleScale(settings.domain[i + 1])), | |
| startAngle: deg2Rad(settings.angleScale(settings.domain[i])) | |
| }; | |
| }); | |
| var arcSegments = arc.selectAll('path').data(arcSegmentData); | |
| arcSegments.enter().append('path') | |
| .each(function (d) { this._current = d; }) | |
| .attr('d', settings.arcGenerator) | |
| .attr('fill', function (d) { return d.color }); | |
| arcSegments.exit().remove(); | |
| arcSegments | |
| .transition(settings.transition) | |
| .attrTween('d', function(d) { | |
| var interpolator = d3.interpolate(this._current, d); | |
| this._current = interpolator(0); | |
| return function(t) { | |
| return settings.arcGenerator(interpolator(t)); | |
| }; | |
| }) | |
| .attr('fill', function (d) { return d.color }) | |
| // Draw gauge labels. | |
| var tickGroup = content.select('.tick-group'); | |
| if (tickGroup.empty()) { | |
| tickGroup = content.append('g').classed('tick-group', true); | |
| } | |
| var labelGroup = content.select('.label-group'); | |
| if (labelGroup.empty()) { | |
| labelGroup = content.append('g').classed('label-group', true); | |
| } | |
| var tickData = settings.angleScale.ticks().map(function(tick) { | |
| return { | |
| angle: settings.angleScale(tick), | |
| text: tick | |
| }; | |
| }); | |
| var ticks = tickGroup.selectAll('line').data(tickData); | |
| ticks.enter() | |
| .append('line') | |
| .each(function(d) { this._current = d.angle; }) | |
| .attr({ | |
| stroke: 'black', | |
| x1: width_2, | |
| y1: height - radius + settings['arc-size'], | |
| x2: width_2, | |
| y2: height - radius, | |
| transform: function(d) { | |
| return 'rotate(' + d.angle + ',' + width_2 + ',' + height + ')'; | |
| } | |
| }); | |
| ticks.exit().remove(); | |
| ticks.transition(settings.transition) | |
| .attr({ | |
| x1: width_2, | |
| y1: height - radius + settings['arc-size'], | |
| x2: width_2, | |
| y2: height - radius | |
| }) | |
| .attrTween('transform', function(d) { | |
| var interpolator = d3.interpolate(this._current, d.angle); | |
| this._current = d.angle; | |
| return function(t) { | |
| return 'rotate(' + interpolator(t) + ',' + width_2 + ',' + height + ')'; | |
| } | |
| }); | |
| var labels = labelGroup.selectAll('text').data(tickData); | |
| labels.enter() | |
| .append('text') | |
| .each(function(d) { this._current = d.angle; }) | |
| .text(function(d) { return d.text; }) | |
| .attr({ | |
| 'text-anchor': 'middle', | |
| x: width_2, | |
| y: height - radius, | |
| transform: function(d) { | |
| return 'rotate(' + d.angle + ',' + width_2 + ',' + height + ')'; | |
| } | |
| }); | |
| labels.exit().remove(); | |
| labels.transition(settings.transition) | |
| .attr({ | |
| x: width_2, | |
| y: height - radius - 5 | |
| }) | |
| .attrTween('transform', function(d) { | |
| var interpolator = d3.interpolate(this._current, d.angle); | |
| this._current = d.angle; | |
| return function(t) { | |
| return 'rotate(' + interpolator(t) + ',' + width_2 + ',' + height + ')'; | |
| } | |
| }); | |
| // Draw gauge indicator | |
| var indicator = content.select('.indicator'); | |
| if (indicator.empty()) { | |
| content.append('circle') | |
| .classed('indicator__knob', true) | |
| .attr({ | |
| cx: width_2, | |
| cy: height, | |
| r: 5 | |
| }); | |
| indicator = content.append('line').datum(datum.value) | |
| .classed('indicator', true) | |
| .each(function(d) { this._current = d; }) | |
| .attr({ | |
| stroke: 'black', | |
| 'stroke-width': 2, | |
| x1: width_2, | |
| y1: height, | |
| x2: width_2, | |
| y2: height - radius | |
| }) | |
| .attr('transform', function(d) { | |
| return 'rotate(' + settings.angleScale(d) + ',' + width_2 + ',' + height + ')' | |
| }); | |
| } | |
| indicator.datum(datum.value) | |
| .transition(settings.transition) | |
| .attr({ | |
| x1: width_2, | |
| y1: height, | |
| x2: width_2, | |
| y2: height - radius | |
| }) | |
| .attrTween('transform', function(d) { | |
| var interpolator = d3.interpolate(this._current, d); | |
| this._current = d; | |
| return function(t) { | |
| return 'rotate(' + settings.angleScale(interpolator(t)) + ',' + width_2 + ',' + height + ')'; | |
| } | |
| }); | |
| }; | |
| chart.arcSize = getterSetter('arc-size'); | |
| chart.angle = getterSetter('angle', function(value) { | |
| settings.angleScale.range([-value / 2, value / 2]); | |
| }); | |
| chart.domain = getterSetter('domain', function(value) { | |
| settings.angleScale.domain([value[0], value[value.length -1]]); | |
| }); | |
| chart.margin = getterSetter('margin'); | |
| chart.range = getterSetter('range'); | |
| chart.transition = getterSetter('transition'); | |
| return chart; | |
| } |
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