Stretched chord based on Visual cinnamon example (PHS II data)

<!DOCTYPE html>
<meta charset="utf-8">
<style>

body {
  font: 10px sans-serif;
  background-color: #EEEEEE;
}

.group-tick line {
  stroke: #000;
}

.ribbons {
  fill-opacity: 0.67;
}

.Dummy {
  opacity: 0.0
}

</style>

var early_matrix = [
  [0,0,0,0,0,0,0,0,0,0,0,0,0.0151285754993426,0,0.0518473002003632,2.73541007078455,0.828620573151337,0.0451953090163421,0.163844194032935,35.836239436967],
  [0,0,0,0,0,0,0,0,0,0,0,0,0,0.000614443660384447,0.0450806761442615,3.29089250571661,0.664772149502223,0.0441396454260848,0.12363369716987,17.2677970070127],
  [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0.152434855594515,0.230299361448876,0.0145558714545113,0.0377076694258343,0.399385004063615],
  [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0.0136252628263728,0.808411208095924,1.30964638874836,0.138725540798948,0.110463993669776,2.74907804005385],
  [0,0,0,0,0,0,0,0,0,0,0,0,0.00274213125665268,0.0334839218208002,0.949088664316574,0.685848404858807,0.612733195103625,18.5803972046021,1.0027956709223,0.495545371899067],
  [0,0,0,0,0,0,0,0,0,0,0,0,0.00542307567466032,0.0034325453259032,0.0202258691065055,0.266141217281322,0.130766155456765,1.26434921610419,0.0271512489887922,0.0408782957360215],
  [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0.00543514538225534,0,0,0,0.218956674741719],
  [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0.53809516216267,0.595757265694071,0,0.0824805134994678,0.99497885645232],
  [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0.00874830882224031,1.05676121748795,3.08883254587064,0.00947107224970259,0.336216261098241,1.10680324939578],
  [0,0,0,0,0,0,0,0,0,0,0,0,0,0.00564072204620875,0.00620034608352639,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0.0841850465218208,0.0637958618746478,0.0214007679982468,0.529790502585937,0.034683791559702],
  [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0.0132157194602717],
  [0.0151285754993426,0,0,0,0.00274213125665268,0.00542307567466032,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
  [0,0.000614443660384447,0,0,0.0334839218208002,0.0034325453259032,0,0,0,0.00564072204620875,0,0,0,0,0,0,0,0,0,0],
  [0.0518473002003632,0.0450806761442615,0,0.0136252628263728,0.949088664316574,0.0202258691065055,0,0,0.00874830882224031,0.00620034608352639,0,0,0,0,0,0,0,0,0,0],
  [2.73541007078455,3.29089250571661,0.152434855594515,0.808411208095924,0.685848404858807,0.266141217281322,0.00543514538225534,0.53809516216267,1.05676121748795,0,0.0841850465218208,0,0,0,0,0,0,0,0,0],
  [0.828620573151337,0.664772149502223,0.230299361448876,1.30964638874836,0.612733195103625,0.130766155456765,0,0.595757265694071,3.08883254587064,0,0.0637958618746478,0,0,0,0,0,0,0,0,0],
  [0.0451953090163421,0.0441396454260848,0.0145558714545113,0.138725540798948,18.5803972046021,1.26434921610419,0,0,0.00947107224970259,0,0.0214007679982468,0,0,0,0,0,0,0,0,0],
  [0.163844194032935,0.12363369716987,0.0377076694258343,0.110463993669776,1.0027956709223,0.0271512489887922,0,0.0824805134994678,0.336216261098241,0,0.529790502585937,0,0,0,0,0,0,0,0,0],
  [35.836239436967,17.2677970070127,0.399385004063615,2.74907804005385,0.495545371899067,0.0408782957360215,0.218956674741719,0.99497885645232,1.10680324939578,0,0.034683791559702,0.0132157194602717,0,0,0,0,0,0,0,0]
];

// var early_matrix = [
//   [0, 0, 0, 0.1, 5 + 9.9, 15],
//   [0, 0, 0, 0.1, 15 + 4.9, 20],
//   [0, 0, 0, 0.1, 14.9 + 5, 5],
//   [0.1, 0.1, 0.1, 0, 0, 0],
//   [5 + 9.9, 15 + 4.9, 5 + 14.9, 0, 0, 0],
//   [15, 20, 5, 0, 0, 0]
// ];

// var early_matrix = [
//   [0, 0, 10, 15, 5],
//   [0, 0, 6, 8, 10],
//   [10, 6, 0, 0, 0],
//   [15, 8, 0, 0, 0],
//   [5, 10, 0, 0, 0]
// ];

var group1_names = ["Private hospital", "Government hospital", "Govt Mother & Child Health center", "Private clinic/ maternity home", "Respondent's home", "Other home", "Other public", "RHC", "BHU", "Other_","CMW home/birth station","Other private medical"];
var group2_names = ["Other","No one","Relatives/ Friends","Nurse","Lady Health Vistor (LHV)","Traditional Birth Attendant (TBA)","Community Midwife (CMW)","Doctor"];

// var group1_names = ["Doctor", "Nurse", "LHV"];
// var group2_names = ["Public", "Private", "RHC"];

var group_names = group1_names.concat("Dummy", group2_names, "Dummy");

total_no = early_matrix[1].length;
empty_area_perc = 0.4
empty_am = total_no * empty_area_perc;
var offset_angle = ((empty_am)/(empty_am + total_no)) * Math.PI/ 2;
var offset_degrees = offset_angle * (180/ Math.PI);

console.log(offset_degrees);

function startAngle(d) {return d.startAngle + offset_angle};
function endAngle(d) {return d.endAngle + offset_angle};

// function to add dummy arrays in the matrix for stretched chord
function add_dummies_to_matrix(matrix, empty_area_perc){
  // create a single array from the input matrix
  var matrix_arr = matrix.reduce(function(result, elem){return result.concat(elem)})
  // take the sum of the above array and divide by 2 (to get the total sum)
  var total_sum = matrix_arr.reduce(function(result, elem) { return result + elem })/ 2;

// gettimg the number of sub groups in group 1 and total number of subgroups
  var group2_no = group2_names.length;
  var group1_no = group1_names.length;
  var total_no = matrix[1].length;

// adding zeros for dummys
  for (var i = 0; i < matrix.length; i++){
    //early_matrix[i] = early_matrix[i].push(0);
    var group1_vals = matrix[i].slice(0, group1_no);
    var group2_vals = matrix[i].slice(group1_no,total_no);

matrix[i] = group1_vals.concat(0, group2_vals, 0);
  }

// getting empty/ dummy no through the percentage of empty/ dummy arc
  var empty_no = empty_area_perc * total_sum;

// adding the empty_no into the dummy arrays
  zeros1 = a = new Array(total_no + 2).fill(0);
  zeros1[total_no + 2 - 1] = empty_no;
  zeros1 = [zeros1];

zeros2 = new Array(total_no + 2).fill(0);
  zeros2[group1_no] = empty_no;
  zeros2 = [zeros2];

// cutting the matrix into two halfs to put in dummy arrays
  matrix_1 = matrix.slice(0, group1_no);
  matrix_2 = matrix.slice(group1_no, total_no);

// concatenating dummy arrays with the matrix halves
  var matrix_with_dummy = matrix_1.concat(zeros1, matrix_2, zeros2);

return matrix_with_dummy;
}

var matrix = add_dummies_to_matrix(early_matrix, empty_area_perc);

console.log(matrix);

var svg = d3.select("svg"),
    width = +svg.attr("width"),
    height = +svg.attr("height"),
    outerRadius = Math.min(width, height) * 0.5 - 85 , //205
    innerRadius = outerRadius - 13;

var formatValue = d3.formatPrefix(",.0", 1);

var chord = d3.chord()
    .padAngle(0.015)
    .sortSubgroups(d3.descending)
    //.pullOutSize(pullOutSize);
    // .startAngle(startAngle)
    // .endAngle(endAngle);

var arc = d3.arc()
    .innerRadius(innerRadius)
    .outerRadius(outerRadius)
    .startAngle(startAngle)
    .endAngle(endAngle);

var pullOutSize = 15;

var ribbon = stretchedChord()
  //d3.ribbon()
    .radius(innerRadius)
    .startAngle(startAngle)
    .endAngle(endAngle)
    .pullOutSize(pullOutSize);

// var group1_names = ["Doctor", "Nurse", "LHV"];
// var group2_names = ["Public", "Private", "RHC"];

console.log(group_names);

// var color = d3.scaleOrdinal()
//     .domain(d3.range(8))
//     .range(["#D3D3D3", "#D3D3D3", "#D3D3D3", "#FFFFFF","#000000", "#FFDD89", "#957244", "#FFFFFF"]);

var g = svg.append("g")
    .attr("transform", "translate(" + width / 2 + "," + height / 2 + ")")
    .datum(chord(matrix));

var group = g.append("g")
    .attr("class", "groups")
  .selectAll("g")
  .data(function(chords) { return chords.groups; })
  .enter().append("g")
  .attr("class", function(d) { return group_names[d.index]})
  .classed("holder_group", true);

var non_dummy_grps = d3.selectAll(".groups")
                        .selectAll("g :not(.Dummy)");

console.log(chord(matrix));

group.append("path")
    //.style("fill", function(d) { return color(d.index); })
    .style("fill", "#6699ff")
    // #6699ff
    //.style("stroke", function(d) { return d3.rgb(color(d.index)).darker(); })
    .attr("class", function(d) { return group_names[d.index] } )
    .classed("group_arc", true)
    .attr("d", arc)
    .attr("transform",function(d, i){
      d.pullOutSize = pullOutSize * ((d.startAngle + d.endAngle)/2  > Math.PI ? -1 : 1);
      return "translate(" + d.pullOutSize + "," + 0 + ")";
    })

d3.selectAll('.holder_group')
    .on("mouseover", fade(0.15, 0.95, 1))
    .on("mouseout", fade(0.67, 0.67, 0.1));
    //})

// groupTick.append("line")
//     .attr("x2", 6);
//
// groupTick
//   .filter(function(d) { return d.value % 5 === 0; })
//   .append("text")
//     .attr("x", 8)
//     .attr("dy", ".35em")
//     .attr("transform", function(d) { return d.angle > Math.PI ? "rotate(180) translate(-16)" : null; })
//     .style("text-anchor", function(d) { return d.angle > Math.PI ? "end" : null; })
//     .text(function(d) { return formatValue(d.value); });

// try adding the labels

var label_pad = 10;

group.append("text")
    .attr("class", function(d) { return group_names[d.index] } )
    .each(function(d) { d.angle = (d.startAngle + d.endAngle) / 2; })
    .text(function(d, i) { return group_names[d.index] } )
    .attr("text-anchor", function(d) { return d.angle > Math.PI ? "end" : null; })
    .attr("transform", function(d) {
        d.pullOutSize = pullOutSize * (d.angle > Math.PI ? -1 : 1);
        return "translate(" + d.pullOutSize + ") "
            + "rotate(" + ((d.angle + offset_angle) * 180 / Math.PI - 90) + ")"
            + "translate(" + (outerRadius + label_pad) + ")"
            + (d.angle > Math.PI ? "rotate(180)" : "");
    })
    .style("opacity", function(d, i) { return (d.value/ 100) < 0.01 ? 0.1 : 1 })

g.append("g")
    .attr("class", "ribbons")
  .selectAll("path")
  .data(function(chords) { return chords; })
  .enter().append("path")
    .attr("d", ribbon)
    //.style("fill", function(d) { return color(d.target.index); })
    .style("fill", "#B0BEC5")
    .attr("class", function(d, i) { return d.target.index == total_no + 1 ? "Dummy" : "NonDummy"; })
    .classed("ribbon_path", true);
    //.style("stroke", function(d) { return d3.rgb(color(d.target.index)).darker(); });

// Returns an array of tick angles and values for a given group and step.
function groupTicks(d, step) {
  var k = (d.endAngle - d.startAngle) / d.value;
  return d3.range(0, d.value, step).map(function(value) {
    return {value: value, angle: value * k + (d.startAngle + offset_angle + 0.005)};
  });
}

//var svg = s3.select("svg");

// Returns an event handler for fading a given chord group.
function fade(opacity1, opacity2, text_opacity) {
  return function(d, i) {
    var group_idx = d.index
    var value = d.value;
    d3.selectAll(".ribbon_path")
      .filter(function(d) { return d.source.index != group_idx && d.target.index != group_idx; })
      .transition()
        .style("fill-opacity", opacity1);
    d3.selectAll(".ribbon_path")
      .filter(function(d) { return d.source.index == group_idx && d.target.index == group_idx; })
      .transition()
        .style("fill-opacity", opacity2);

d3.select(this).select('text')
      .filter(function(d) { return d.value/ 100 < 0.01 })
      .transition()
        .style("opacity", text_opacity);
  };
}

</script>

https://d3js.org/d3.v4.min.js