User:Fbstj/edits-pie
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<graph> {
"version": 2, "width": 300, "height": 300, "data": [ { // Data is retrieved from the MediaWiki API. By default it uses current wiki's "Extension by category" "name": "table", "url": "wikiapi://coppermind.net/?action=query&format=json&list=allusers&auprop=editcount&aulimit=max&augroup=editor&auwitheditsonly=1", // We are only interested in the content of query.allusers subelement. "format": {"property": "query.allusers","type": "json"}, "transform": [ // sort in descending order using category size as the sort key {"type": "sort","by": "-editcount"}, // To visualize, use "pie" transformation to add layout_start, layout_end, and layout_mid fields to each page object // These fields contain angles at which to start and stop drawing arcs. First element's start will be 0, and last element's end will be 360 degrees (in radians) {"type": "pie","field": "editcount"} ] } ],
// "legends": [{"title": "Legend","fill": "color"}],
// Scales are like functions -- marks use them to convert a data value into a visual value, like x or y coordinate on the graph, or a color value. "scales": [ { // This scale will be used to assign a color to each slice, using a palette of 10 colors "name": "color", "domain": {"data": "table","field": "name"}, "range": "category10", "type": "ordinal" } ], "marks": [ { // This mark draws the actual pie chart from the data source // Each element is an arc between layout_start and layout_end angles (as calculated by the pie transformation) // drawn with a given radius, stroke, and fill. "from": {"data": "table"}, "type": "arc", "properties": { "enter": { "fill": {"scale": "color","field": "name"}, "outerRadius": {"value": 200}, "startAngle": {"field": "layout_start"}, "endAngle": {"field": "layout_end"}, "stroke": {"value": "white"}, "strokeWidth": {"value": 1} } } }, { // This mark draws labels around the pie chart after the pie chart has been drawn "type": "text", // Before drawing, we need to perform a number of calculations to figure out the exact location and orientation of the text "from": { "data": "table", "transform": [ // For each data point (datum), each of these transformations will be ran in order. // Formula transformation evaluates the expression and assigns result to the datapoint // Size of the pie slice, in degrees: sliceSize = (end - start) * 180 / Pi { "type": "formula", "field": "sliceSize", "expr": "(datum.layout_end - datum.layout_start)*180/PI" }, // Draw text only if the slice of the arc is more than 2 degrees to avoid overcrowding { "type": "filter", "test": "datum.sliceSize > 2" }, // Remove namespace from the text - keeps only text after the first ':' symbol, limits to 40 chars. { "type": "formula", "field": "name", "expr": "substring(datum.name, 1+indexof(datum.name,':'), 40) +': '+ datum.editcount + ' ('+ round(datum.sliceSize * 100 / 180) +'%)'" }, // Determine the side of the pie chart we are on - left or right. { "type": "formula", "field": "invert", "expr": "datum.layout_mid*180/PI < 180 ? 1 : -1" }, // If on the left, the text should be right-aligned (go from the rim inward) { "type": "formula", "field": "align", "expr": "datum.invert < 0 ? 'left' : 'right'" }, // At what angle should the text be drawn relative to the point on the circle { "type": "formula", "field": "angle", "expr": "(datum.layout_mid*180/PI)-90*datum.invert" }, // Make font smaller for smaller pie slices { "type": "formula", "field": "fontSize", "expr": "datum.sliceSize > 20 ? 15 : (datum.sliceSize > 10 ? 14 : 10)" }, // Make font bold for largest pie slices { "type": "formula", "field": "fontWeight", "expr": "datum.sliceSize > 15 ? 'bold' : 'normal'" } ] }, "properties": { "enter": { // Use the fields calculated in the transformation to draw category names "align": {"field": "align"}, "angle": {"field": "angle"}, "baseline": {"value": "middle"}, "fill": {"value": "black"}, "fontSize": {"field": "fontSize"}, "fontWeight": {"field": "fontWeight"}, "radius": {"value": 270}, "text": {"field": "name"}, "theta": {"field": "layout_mid"} } } } ]
} </graph>