d3圖表中的兩個傳奇問題

Question

我有一個內置d3的圖表來顯示誰在說話以及在播放過程中的位置。字符由顏色條表示，我想提供一個圖例。但是，我的圖例代碼垂直顯示在單個列中，並多次顯示相同的字符名稱。我知道後者是因爲它解析了json中的每條記錄，但我不知道如何僅提供每個字符一次，而不是像提供我的代碼中的位置列表一樣提供字符列表。有沒有辦法，我可以從json做到這一點呢？

另外，如何組織圖例中的圖例以利用圖表左上部分的空白？我用我目前在https://jsfiddle.net/3f7xrgeb/上的代碼創建了一個小提琴，並且在下面粘貼了它。我的工作副本（如果小提琴不顯示）在http://www.matthewedavis.net/Magdalene_playtext/test_bars.html。

任何幫助，將不勝感激。

var margin = {top: 50, right: 150, bottom: 50, left: 150}, 
     w = 2500 - margin.left - margin.right, 
     h = 500 - margin.top - margin.bottom; 

    d3.json("http://www.matthewedavis.net/Magdalene_playtext/test_chart.json", function(json) { 

     var data = json.items; 

     var test = function(d) { return d.starting_line + d.duration; }; 

     var stage_directions = ([44, 49, 114, 140, 209, 217, 249, 257, 265, 277, 305, 334, 358, 381, 398, 409, 440, 470, 491, 547, 555, 564, 572, 587, 614, 630, 640, 691, 704, 725, 743, 775, 793, 818, 823, 841, 845, 868, 872, 888, 902, 910, 920, 925, 963, 993, 1005, 1023, 1031, 1047, 1061, 1096, 1125, 1133, 1143, 1178, 1210, 1228, 1281, 1293, 1336, 1349, 1376, 1395, 1439, 1446, 1454, 1538, 1554, 1562, 1578, 1598, 1610, 1618, 1642, 1646, 1716, 1725, 1743, 1781, 1791, 1797, 1843, 1863, 1887, 1915, 1923, 1939 ,1972, 1989, 2019, 2031, 2039, 2045, 2073, 2085, 2101, 2123]) 

     var x = d3.scale.linear() 
     .domain([0, 2200]) 
     .range([0, w]); 

     var y = d3.scale.ordinal() 
     .domain(["The priest's cell","The Cloud","Wilderness","The mountain","The Lodge","Marseilles","The Ship","Heaven","Heathen Temple","Sepulchre","The Stations","Palace of the King of Marseilles","Lazarus' tomb","Simon the Leper's House","Arbor","Jherusalem","Tavern","Hellmouth","The Place","Stage Above Hell","King of Flesh's location","King of the World's location","Pilate's location","Herod's location","Magdalene Castle","Tiberius' Palace"]) 
     .rangeBands([0, h]); 

     var yAxis = d3.svg.axis() 
     .scale(y) 
     .orient("left"); 

     var xAxis = d3.svg.axis() 
     .scale(x) 
     .orient("bottom"); 

     var svg = d3.select("body").append("svg") 
     .attr("width", w + margin.left + margin.right) 
     .attr("height", h + margin.top + margin.bottom) 
     .append("g") 
     .attr("transform", "translate(" + margin.left + "," + margin.top + ")"); 

     svg.append("text") 
     .attr("transform", "translate(" + (w/2) + " ," + (h + margin.bottom - 5) +")") 
     .style("text-anchor", "middle") 
     .text("Line Number"); 

     var t; 
     for (t in stage_directions){ 
     svg.append("rect") 
     .attr("class", "overlay") 
     .attr("x",stage_directions[t]) 
     .attr("width", 1) 
     .attr("height", h) 
     .style ("fill", "black") 
     .style ("opacity", 0.3); 
    } 

     svg.append("rect") 
     .attr("class", "overlay") 
     .attr("x",1) 
     .attr("width", 1133) 
     .attr("height", h) 
     .style ("fill", "red") 
     .style ("opacity", 0.1); 

     svg.append("rect") 
     .attr("class", "overlay") 
     .attr("x",1133) 
     .attr("width", 857) 
     .attr("height", h) 
     .style ("fill", "yellow") 
     .style ("opacity", 0.1); 

     svg.append("rect") 
     .attr("class", "overlay") 
     .attr("x",1990) 
     .attr("width", 134) 
     .attr("height", h) 
     .style ("fill", "green") 
     .style ("opacity", 0.1); 

     svg.append("g") 
     .attr("class", "x axis") 
     .attr("transform", "translate(0," + h + ")") 
     .call(xAxis); 

     svg.append("g") 
     .attr("class", "y axis") 
     .call(yAxis) 

     var bars = svg.selectAll(".bar") 
     .data(data) 
     .enter() 
     .append("rect") 
     .attr("class", function(d, i) {return "bar " + d.character;}) 
     .attr("x", function(d, i) {return d.starting_line;}) 
     .attr("y", function(d, i) {return y(d.location);}) 
     .attr("width", function(d, i) {return d.duration;}) 
     .attr("height", 15) 
     .style("fill", function(d,i) {return "#" + d.color;}); 


     var legend = svg.selectAll(".legend") 
     .data(data) 
     .enter().append("g") 
     .attr("class", "legend") 
     .attr("transform", function(d, i) { return "translate(0," + i * 20 + ")"; }); 

     legend.append("rect") 
     .attr("x", 10) 
     .attr("width", 10) 
     .attr("height", 10) 
     .style("fill", function(d,i) {return "#" + d.color;}); 

     legend.append("text") 
     .attr("x", 22) 
     .attr("y", 5) 
     .attr("dy", ".35em") 
     .text(function(d) { return d.character; }); 

     svg.append("g") 
     .attr("class", "legend") 
     .call(legend) 
    }); 

Answer 1

試試這個：

首先，創建一個陣列的字符列表，避免重複：

var listCharacters = d3.set(data.map(function(d){ return d.character})).values(); 

然後，用它作爲你的傳奇數據：

var legend = svg.selectAll(".legend") 
.data(listCharacters) 
.enter() 
//the test of the code... 

並更改text：

.text(function(d,i){ return listCharacters[i]}); 

至於顏色，做同樣的：

var listColors = d3.set(data.map(function(d){ return d.colour})).values(); //check the spelling in your object 

和彩色矩形根據指數：

.attr("fill", function(d,i){ return listColors[i]}); 

要了解它做什麼，請閱讀本： https://github.com/mbostock/d3/wiki/Arrays