The psy curve

This example demonstrates the construction of the psy curve.

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

.frame {
  fill: none;
  stroke: #000;
}

.axis text {
  font: 10px sans-serif;
}

.axis line,
.axis circle {
  fill: none;
  stroke: #777;
  stroke-dasharray: 1,4;
}

.axis :last-of-type circle {
  stroke: #333;
  stroke-dasharray: none;
}

.line {
  fill: none;
  stroke: red;
  stroke-width: 1.5px;
}

</style>
<body>
<script src="https://d3js.org/d3.v3.min.js"></script>
<script>

var data = d3.range(0, 72 * Math.PI, .01).map(function(t) {
  return [t, psy_x(t), psy_y(t)];
});

var width = 960,
    height = 500,
    radius = Math.min(width, height) / 2 - 30;

var r = d3.scale.linear()
    .domain([0, .5])
    .range([0, radius]);

//var line = d3.svg.line.radial()
//    .radius(function(d) { return r(d[1]); })
//    .angle(function(d) { return -d[0] + Math.PI / 2; });

var pi = Math.PI
  , sin = Math.sin
  , sgn = function(x) { return x < 0 ? -1 : x ? 1 : 0; }
  , sqrt = Math.sqrt
  , theta = function(x) { return x < 0 ? 0 : 1; }
  , line = d3.svg.line().x(psy_x).y(psy_y).interpolate("basis");

var svg = d3.select("body").append("svg")
    .attr("width", width)
    .attr("height", height)
  .append("g")
    .attr("transform", "translate(" + width / 2 + "," + height / 2 + ")");

var gr = svg.append("g")
    .attr("class", "r axis")
  .selectAll("g")
    .data(r.ticks(5).slice(1))
  .enter().append("g");

gr.append("circle")
    .attr("r", r);

gr.append("text")
    .attr("y", function(d) { return -r(d) - 4; })
    .attr("transform", "rotate(15)")
    .style("text-anchor", "middle")
    .text(function(d) { return d; });

var ga = svg.append("g")
    .attr("class", "a axis")
  .selectAll("g")
    .data(d3.range(0, 360, 30))
  .enter().append("g")
    .attr("transform", function(d) { return "rotate(" + -d + ")"; });

ga.append("line")
    .attr("x2", radius);

ga.append("text")
    .attr("x", radius + 6)
    .attr("dy", ".35em")
    .style("text-anchor", function(d) { return d < 270 && d > 90 ? "end" : null; })
    .attr("transform", function(d) { return d < 270 && d > 90 ? "rotate(180 " + (radius + 6) + ",0)" : null; })
    .text(function(d) { return d + "°"; });

svg.append("path")
    .datum(data)
    .attr("class", "line")
    .attr("d", line);

function psy_x(t) {
  return ((-25/37*sin(58/37-4*t)+809/54*sin(t+11/7)+9/19*sin(2*t+108/23)+17/23*sin(3*t+49/31)+11/12*sin(5*t+107/68)-17/27)*theta(71*pi-t)*theta(t-67*pi)+(-6/49*sin(39/25-8*t)-3/32*sin(39/25-7*t)-2/11*sin(64/41-6*t)-107/68*sin(36/23-2*t)-228/31*sin(69/44-t)+17/36*sin(3*t+11/7)+11/49*sin(4*t+113/24)+1/63*sin(5*t+29/19)+1091/31)*theta(67*pi-t)*theta(t-63*pi)+(35/8*sin(t+11/7)+15/23*sin(2*t+52/33)+11/30*sin(3*t+11/7)+1/18*sin(4*t+63/40)-556/17)*theta(63*pi-t)*theta(t-59*pi)+(-104/31*sin(27/41-2*t)+523/45*sin(t+29/25)+40/37*sin(3*t+25/41)+21/17*sin(4*t+121/26)+148/27)*theta(59*pi-t)*theta(t-55*pi)+(-9/20*sin(13/11-18*t)-9/26*sin(88/63-17*t)-15/41*sin(81/161-15*t)-7/15*sin(25/18-14*t)-59/89*sin(13/34-12*t)-87/38*sin(9/10-6*t)-117/22*sin(23/42-5*t)+582/13*sin(t+64/37)+88/25*sin(2*t+229/49)+1458/47*sin(3*t+48/23)+167/50*sin(4*t+151/50)+135/22*sin(7*t+93/32)+143/102*sin(8*t+100/33)+2/21*sin(9*t+169/47)+41/124*sin(10*t+84/19)+7/39*sin(11*t+147/73)+15/17*sin(13*t+69/17)+6/29*sin(16*t+2/25)+7/43*sin(19*t+57/16)+5/36*sin(20*t+20/53)+225/41)*theta(55*pi-t)*theta(t-51*pi)+(-22/27*sin(21/19-33*t)-23/28*sin(56/75-32*t)-9/14*sin(18/29-31*t)-32/33*sin(145/109-29*t)-11/23*sin(27/38-28*t)-91/114*sin(26/31-26*t)-47/40*sin(73/55-24*t)-54/53*sin(8/21-21*t)-38/25*sin(65/43-19*t)-108/65*sin(11/17-14*t)-11/27*sin(289/193-9*t)+3415/31*sin(t+65/34)+916/35*sin(2*t+168/41)+85/16*sin(3*t+37/41)+92/35*sin(4*t+107/32)+107/27*sin(5*t+14/31)+47/25*sin(6*t+7/11)+35/12*sin(7*t+49/26)+26/23*sin(8*t+82/21)+48/25*sin(10*t+26/103)+35/38*sin(11*t+23/32)+15/22*sin(12*t+160/41)+285/286*sin(13*t+3/38)+8/19*sin(15*t+336/79)+48/31*sin(16*t+10/3)+122/87*sin(17*t+37/23)+68/31*sin(18*t+1/27)+11/9*sin(20*t+58/21)+49/44*sin(22*t+4)+22/29*sin(23*t+68/53)+1/2*sin(25*t+86/23)+17/37*sin(27*t+148/33)+21/29*sin(30*t+137/30)+12/29*sin(34*t+202/47)+15/34*sin(35*t+10/29)+861/37)*theta(51*pi-t)*theta(t-47*pi)+(-5/13*sin(9/14-8*t)-33/25*sin(105/106-6*t)-12/61*sin(47/46-5*t)-17/35*sin(6/11-4*t)-617/35*sin(58/41-2*t)+97/24*sin(t+49/11)+93/43*sin(3*t+53/24)+52/69*sin(7*t+19/8)+16/31)*theta(47*pi-t)*theta(t-43*pi)+(-10/31*sin(55/39-6*t)+708/23*sin(t+53/28)+10/17*sin(2*t+303/70)+201/200*sin(3*t+275/92)+8/15*sin(4*t+129/29)+2/23*sin(5*t+110/41)+18/89*sin(7*t+73/30)+949/15)*theta(43*pi-t)*theta(t-39*pi)+(-22/41*sin(42/41-5*t)-9/19*sin(11/31-3*t)+1168/41*sin(t+59/37)+13/21*sin(2*t+382/83)+15/29*sin(4*t+105/29)+7/17*sin(6*t+67/19)-2875/47)*theta(39*pi-t)*theta(t-35*pi)+(-15/19*sin(1/26-14*t)-111/31*sin(7/31-4*t)+3698/39*sin(t+31/20)+135/22*sin(2*t+1/35)+136/11*sin(3*t+71/46)+57/13*sin(5*t+29/19)+22/25*sin(6*t+80/31)+29/40*sin(7*t+212/47)+31/26*sin(8*t+1/31)+55/27*sin(9*t+51/29)+46/31*sin(10*t+3/23)+27/29*sin(11*t+48/47)+5/21*sin(12*t+49/24)+23/40*sin(13*t+11/9)+13/59*sin(15*t+26/37)-15/16)*theta(35*pi-t)*theta(t-31*pi)+(53/32*sin(t+54/37)+267/26*sin(2*t+239/92)+35/33*sin(3*t+13/34)+8/9*sin(4*t+19/25)+7/15*sin(5*t+17/16)+3/5*sin(6*t+57/22)+15/52*sin(7*t+27/22)+15/49*sin(8*t+28/23)+2/17*sin(9*t+180/77)+3/38*sin(10*t+64/35)+5/34*sin(11*t+35/24)+3/31*sin(12*t+21/22)-5662/43)*theta(31*pi-t)*theta(t-27*pi)+(-6/25*sin(12/47-9*t)+77/36*sin(t+159/35)+114/11*sin(2*t+37/8)+13/19*sin(3*t+77/41)+11/27*sin(4*t+128/71)+6/11*sin(5*t+191/52)+96/193*sin(6*t+19/11)+3/17*sin(7*t+7/4)+3/17*sin(8*t+6/7)+3/20*sin(10*t+31/43)+4078/31)*theta(27*pi-t)*theta(t-23*pi)+(-21/64*sin(2/21-7*t)-35/58*sin(29/33-6*t)-5/26*sin(13/19-5*t)+3153/26*sin(t+29/19)+35/27*sin(2*t+67/23)+19/9*sin(3*t+32/7)+3/14*sin(4*t+19/18)-12/7)*theta(23*pi-t)*theta(t-19*pi)+(-19/30*sin(19/24-16*t)-10/23*sin(41/27-15*t)-66/67*sin(17/21-14*t)-43/42*sin(1/64-13*t)-41/19*sin(16/33-8*t)+28281/404*sin(t+114/31)+756/43*sin(2*t+904/201)+817/41*sin(3*t+25/32)+371/43*sin(4*t+208/45)+80/21*sin(5*t+68/37)+139/52*sin(6*t+31/7)+160/61*sin(7*t+69/43)+37/31*sin(9*t+128/43)+33/67*sin(10*t+14/17)+11/12*sin(11*t+9/4)+13/33*sin(12*t+69/59)+9/44*sin(17*t+96/61)+17/36*sin(18*t+1/40)+5/17*sin(19*t+83/104)+5/18*sin(20*t+7/10)+23/57*sin(21*t+91/29)+5/37*sin(22*t+5/3)+11/30*sin(23*t+177/62)+2/21*sin(24*t+63/17)+9/41*sin(25*t+111/28)+4/33*sin(26*t+159/44)+7/29*sin(27*t+75/28)+2/9*sin(28*t+134/89)+3/20*sin(29*t+80/43)+1/20*sin(30*t+71/30)+4/29*sin(31*t+137/76)+1/53*sin(32*t+34/29)+5/33*sin(33*t+12/5)+4/27*sin(34*t+7/23)+2/29*sin(35*t+28/13)+2302/41)*theta(19*pi-t)*theta(t-15*pi)+(-20/29*sin(3/25-11*t)-53/25*sin(17/16-7*t)-293/21*sin(17/37-5*t)-853/43*sin(107/71-3*t)+2467/29*sin(t+13/10)+307/9*sin(2*t+85/41)+443/28*sin(4*t+41/24)+127/27*sin(6*t+181/41)+79/33*sin(8*t+74/19)+173/69*sin(9*t+341/146)+17/21*sin(10*t+152/45)+41/31*sin(12*t+110/29)+36/107*sin(13*t+55/14)+27/34*sin(14*t+41/12)+49/30*sin(15*t+26/15)+5/4*sin(16*t+8/15)+13/20*sin(17*t+67/46)+11/12*sin(18*t+31/37)+47/53*sin(19*t+30/19)+35/36*sin(20*t+21/19)+29/37*sin(21*t+47/39)+23/30*sin(22*t+32/23)+29/38*sin(23*t+66/31)+7/11*sin(24*t+42/37)+5/27*sin(25*t+211/49)+5/23*sin(26*t+141/49)+1/6*sin(27*t+113/25)+11/37*sin(28*t+152/83)+10/29*sin(29*t+22/39)+14/69*sin(30*t+17/22)+3/41*sin(31*t+51/31)+7/23*sin(32*t+61/28)+7/39*sin(33*t+38/15)+5/19*sin(34*t+47/18)+1/10*sin(35*t+26/37)+5/24*sin(36*t+171/41)-2471/81)*theta(15*pi-t)*theta(t-11*pi)+(-9/41*sin(27/25-14*t)-9/16*sin(67/46-12*t)-63/125*sin(26/21-10*t)-4/23*sin(16/43-9*t)-5/13*sin(11/34-8*t)+319/6*sin(t+26/21)+51/28*sin(2*t+58/21)+353/39*sin(3*t+17/20)+23/16*sin(4*t+9/35)+7/2*sin(5*t+101/67)+31/29*sin(6*t+19/33)+2/23*sin(7*t+92/33)+7/23*sin(11*t+31/52)+4/37*sin(13*t+135/47)+2/29*sin(15*t+206/55)+2534/25)*theta(11*pi-t)*theta(t-7*pi)+(-125/29*sin(53/36-4*t)-845/12*sin(5/29-t)+127/18*sin(2*t+87/44)+334/35*sin(3*t+61/31)+3/8*sin(5*t+95/22)+27/14*sin(6*t+39/32)+8/9*sin(7*t+27/11)+14/9*sin(8*t+131/36)-4169/40)*theta(7*pi-t)*theta(t-3*pi)+(-17/31*sin(3/16-42*t)-7/20*sin(19/22-39*t)-12/31*sin(48/37-38*t)-17/38*sin(38/61-26*t)-50/29*sin(203/204-25*t)-125/42*sin(1/21-20*t)-34/31*sin(28/33-19*t)-317/32*sin(4/11-10*t)-277/33*sin(53/40-9*t)+2468/19*sin(t+12/25)+1180/21*sin(2*t+142/33)+1501/28*sin(3*t+41/27)+281/39*sin(4*t+41/29)+452/37*sin(5*t+115/57)+725/49*sin(6*t+184/67)+591/52*sin(7*t+52/29)+289/25*sin(8*t+141/53)+107/27*sin(11*t+3/10)+281/46*sin(12*t+104/33)+27/8*sin(13*t+108/35)+15/23*sin(14*t+43/18)+27/25*sin(15*t+10/21)+73/34*sin(16*t+99/35)+349/350*sin(17*t+48/23)+18/19*sin(18*t+137/68)+11/16*sin(21*t+14/41)+28/17*sin(22*t+85/22)+33/53*sin(23*t+4/3)+21/32*sin(24*t+7/3)+91/40*sin(27*t+103/27)+10/7*sin(28*t+58/13)+62/35*sin(29*t+49/25)+41/29*sin(30*t+87/35)+27/29*sin(31*t+13/37)+8/17*sin(32*t+49/48)+14/23*sin(33*t+101/31)+2/25*sin(34*t+26/33)+17/30*sin(35*t+101/41)+11/38*sin(36*t+2/33)+73/97*sin(37*t+28/31)+11/27*sin(40*t+167/111)+11/43*sin(41*t+69/19)+1/37*sin(43*t+43/38)+19/43*sin(44*t+71/17)+10/23*sin(45*t+38/9)-371/61)*theta(3*pi-t)*theta(t+pi))*theta(sqrt(sgn(sin(t/2))));
}

function psy_y(t) {
  return ((16/35*sin(t+11/7)+56/27*sin(2*t+96/61)+22/27*sin(3*t+52/33)+74/47*sin(4*t+52/33)+13/32*sin(5*t+67/42)+4093/22)*theta(71*pi-t)*theta(t-67*pi)+(-3/32*sin(61/39-8*t)+341/32*sin(t+11/7)+11/14*sin(2*t+47/10)+23/12*sin(3*t+52/33)+3/20*sin(4*t+53/33)+58/117*sin(5*t+52/33)+3/38*sin(6*t+61/13)+8/41*sin(7*t+58/37)+3055/19)*theta(67*pi-t)*theta(t-63*pi)+(111/10*sin(t+11/7)+10/29*sin(2*t+202/43)+67/50*sin(3*t+11/7)+1/32*sin(4*t+639/137)+5035/31)*theta(63*pi-t)*theta(t-59*pi)+(-35/71*sin(4/17-4*t)-35/34*sin(53/52-3*t)+175/36*sin(t+123/44)+83/27*sin(2*t+133/32)+13847/111)*theta(59*pi-t)*theta(t-55*pi)+(-38/39*sin(19/14-17*t)-13/27*sin(31/22-16*t)-49/39*sin(31/33-13*t)-55/56*sin(4/3-11*t)-76/51*sin(6/29-8*t)+127/35*sin(t+190/67)+1061/78*sin(2*t+61/33)+953/143*sin(3*t+53/16)+48/29*sin(4*t+33/20)+127/26*sin(5*t+317/72)+281/36*sin(6*t+107/39)+48/35*sin(7*t+41/12)+1/8*sin(9*t+3/34)+380/381*sin(10*t+47/26)+27/31*sin(12*t+86/35)+11/32*sin(14*t+10/19)+15/22*sin(15*t+11/27)+2/3*sin(18*t+17/8)+2/29*sin(19*t+181/40)+5/27*sin(20*t+20/13)-14371/74)*theta(55*pi-t)*theta(t-51*pi)+(-14/27*sin(31/23-35*t)-9/17*sin(23/28-34*t)-5/14*sin(18/13-28*t)-9/23*sin(11/20-27*t)-14/29*sin(33/46-26*t)-59/24*sin(44/31-17*t)-137/73*sin(15/22-16*t)-7/23*sin(7/5-12*t)-137/73*sin(11/19-10*t)-44/31*sin(2/33-9*t)-2708/65*sin(16/21-2*t)-818/31*sin(29/33-t)+435/22*sin(3*t+21/20)+113/24*sin(4*t+124/27)+641/95*sin(5*t+51/31)+61/15*sin(6*t+39/11)+303/76*sin(7*t+275/118)+140/29*sin(8*t+127/29)+51/28*sin(11*t+50/29)+43/40*sin(13*t+67/43)+59/46*sin(14*t+173/99)+67/35*sin(15*t+31/24)+45/22*sin(18*t+67/16)+24/19*sin(19*t+20/9)+3/17*sin(20*t+44/27)+18/31*sin(21*t+49/34)+37/62*sin(22*t+11/15)+13/31*sin(23*t+115/67)+16/37*sin(24*t+22/7)+4/35*sin(25*t+26/33)+4/43*sin(29*t+79/17)+11/37*sin(30*t+383/85)+8/35*sin(31*t+259/97)+9/20*sin(32*t+27/10)+22/37*sin(33*t+26/15)+5589/19)*theta(51*pi-t)*theta(t-47*pi)+(-101/30*sin(23/15-3*t)+177/19*sin(t+63/38)+73/19*sin(2*t+58/15)+50/33*sin(4*t+51/14)+5/17*sin(5*t+541/135)+29/35*sin(6*t+125/29)+31/52*sin(7*t+181/41)+7/12*sin(8*t+122/35)+3986/25)*theta(47*pi-t)*theta(t-43*pi)+(-2/25*sin(13/34-7*t)-3/26*sin(9/8-4*t)+430/17*sin(t+6/31)+24/37*sin(2*t+137/35)+50/37*sin(3*t+26/23)+4/45*sin(5*t+268/161)+7/20*sin(6*t+19/6)+8835/43)*theta(43*pi-t)*theta(t-39*pi)+(-11/50*sin(46/55-5*t)+345/13*sin(t+1/10)+67/41*sin(2*t+90/29)+5/2*sin(3*t+2/19)+39/79*sin(4*t+565/141)+23/42*sin(6*t+67/22)+6008/29)*theta(39*pi-t)*theta(t-35*pi)+(-21/53*sin(74/73-15*t)-15/22*sin(78/67-14*t)-291/104*sin(1/14-7*t)-4561/456*sin(2/17-t)+107/44*sin(2*t+46/29)+45/22*sin(3*t+128/51)+553/32*sin(4*t+144/31)+25/16*sin(5*t+127/37)+53/30*sin(6*t+129/29)+1/11*sin(8*t+60/31)+36/23*sin(9*t+107/42)+61/37*sin(10*t+141/32)+26/25*sin(11*t+13/45)+7/23*sin(12*t+64/51)+6/23*sin(13*t+113/45)+7673/35)*theta(35*pi-t)*theta(t-31*pi)+(-4/27*sin(12/17-12*t)-4/15*sin(35/44-10*t)-5/31*sin(4/37-8*t)-10/39*sin(43/65-6*t)+493/19*sin(t+239/54)+7/13*sin(2*t+125/48)+65/16*sin(3*t+95/23)+16/39*sin(4*t+15/41)+5/14*sin(5*t+77/31)+54/163*sin(7*t+181/45)+9/55*sin(9*t+47/19)+4/47*sin(11*t+126/29)+7332/43)*theta(31*pi-t)*theta(t-27*pi)+(-30/91*sin(3/16-7*t)-20/79*sin(37/28-5*t)+247/11*sin(t+88/23)+23/17*sin(2*t+140/37)+461/123*sin(3*t+55/26)+16/31*sin(4*t+36/11)+50/149*sin(6*t+55/54)+3/34*sin(8*t+212/77)+9/43*sin(9*t+1/25)+5/33*sin(10*t+107/35)+1817/11)*theta(27*pi-t)*theta(t-23*pi)+(-14/29*sin(99/85-6*t)-1/20*sin(14/15-3*t)-4823/38*sin(1/17-t)+37/31*sin(2*t+101/27)+212/213*sin(4*t+25/17)+14/37*sin(5*t+119/53)+15/44*sin(7*t+13/51)+6158/33)*theta(23*pi-t)*theta(t-19*pi)+(-5/31*sin(83/82-35*t)-3/26*sin(51/35-33*t)-4/33*sin(22/51-31*t)-5/22*sin(10/23-29*t)-31/61*sin(4/21-17*t)-222/35*sin(21/19-5*t)+2486/43*sin(t+78/17)+684/31*sin(2*t+17/20)+411/32*sin(3*t+49/17)+5/41*sin(4*t+4/27)+61/13*sin(6*t+113/25)+48/25*sin(7*t+39/35)+206/61*sin(8*t+5/23)+11/24*sin(9*t+23/36)+107/106*sin(10*t+5/3)+67/33*sin(11*t+51/23)+41/17*sin(12*t+53/25)+117/34*sin(13*t+50/29)+81/28*sin(14*t+29/28)+43/27*sin(15*t+25/56)+32/37*sin(16*t+5/26)+10/27*sin(18*t+158/43)+34/61*sin(19*t+37/21)+24/49*sin(20*t+31/27)+1/4*sin(21*t+132/79)+11/38*sin(22*t+37/30)+8/31*sin(23*t+119/26)+5/18*sin(24*t+109/34)+4/19*sin(25*t+8/25)+3/23*sin(26*t+25/21)+7/27*sin(27*t+2/19)+4/23*sin(28*t+43/25)+19/75*sin(30*t+43/14)+8/63*sin(32*t+109/24)+1/60*sin(34*t+23/42)-615/34)*theta(19*pi-t)*theta(t-15*pi)+(-1/23*sin(8/13-33*t)-6/19*sin(337/336-28*t)-1/34*sin(13/34-27*t)-11/16*sin(9/11-24*t)-49/74*sin(34/29-23*t)-41/36*sin(77/78-22*t)-35/27*sin(91/92-21*t)-40/27*sin(57/43-19*t)-1/2*sin(6/49-14*t)-31/34*sin(39/29-11*t)-27/14*sin(53/37-5*t)-79/7*sin(9/29-4*t)-597/20*sin(11/21-t)+823/33*sin(2*t+35/29)+281/17*sin(3*t+170/43)+1805/258*sin(6*t+65/21)+293/55*sin(7*t+102/47)+323/108*sin(8*t+5/6)+20/11*sin(9*t+196/43)+27/29*sin(10*t+89/21)+21/8*sin(12*t+29/22)+103/49*sin(13*t+32/53)+27/25*sin(15*t+83/34)+18/25*sin(16*t+91/31)+55/39*sin(17*t+167/40)+233/232*sin(18*t+99/23)+29/24*sin(20*t+51/11)+9/20*sin(25*t+142/31)+2/29*sin(26*t+85/28)+9/40*sin(29*t+73/18)+5/27*sin(30*t+47/13)+2/7*sin(31*t+31/11)+7/26*sin(32*t+53/32)+22/87*sin(34*t+93/26)+5/46*sin(35*t+233/70)+3/22*sin(36*t+87/19)+346/27)*theta(15*pi-t)*theta(t-11*pi)+(-3/35*sin(41/28-14*t)-14/33*sin(40/53-9*t)-38/51*sin(41/47-7*t)-91/11*sin(8/13-3*t)-2058/25*sin(44/35-t)+26/29*sin(2*t+23/9)+41/31*sin(4*t+41/62)+5/4*sin(5*t+1/18)+87/88*sin(6*t+69/53)+17/39*sin(8*t+74/35)+33/98*sin(10*t+113/31)+8/29*sin(11*t+1/176)+17/47*sin(12*t+64/15)+2/15*sin(13*t+208/83)+3/26*sin(15*t+48/17)-3394/23)*theta(11*pi-t)*theta(t-7*pi)+(-27/37*sin(37/34-7*t)-29/8*sin(3/16-4*t)-77/13*sin(3/31-3*t)-3113/38*sin(44/45-t)+96/11*sin(2*t+159/38)+49/82*sin(5*t+21/8)+73/37*sin(6*t+25/27)+31/33*sin(8*t+59/26)-3567/28)*theta(7*pi-t)*theta(t-3*pi)+(-11/36*sin(40/27-45*t)-9/19*sin(14/31-41*t)-10/27*sin(31/26-33*t)-8/11*sin(31/24-31*t)-13/10*sin(13/48-29*t)-66/25*sin(48/43-23*t)-29/14*sin(53/66-19*t)-129/34*sin(2/31-14*t)-77/46*sin(15/22-13*t)-47/41*sin(4/15-12*t)-393/38*sin(24/31-7*t)+3862/51*sin(t+146/31)+1101/8*sin(2*t+78/29)+329/22*sin(3*t+67/26)+246/25*sin(4*t+32/13)+596/49*sin(5*t+101/32)+41/10*sin(6*t+31/18)+287/45*sin(8*t+27/35)+172/29*sin(9*t+66/19)+311/40*sin(10*t+143/37)+97/20*sin(11*t+56/29)+160/39*sin(15*t+377/94)+77/25*sin(16*t+31/30)+74/25*sin(17*t+47/17)+15/14*sin(18*t+113/35)+37/20*sin(20*t+23/29)+24/47*sin(21*t+74/27)+28/41*sin(22*t+135/32)+19/20*sin(24*t+199/149)+33/67*sin(25*t+148/43)+47/36*sin(26*t+55/28)+13/10*sin(27*t+71/33)+19/17*sin(28*t+47/11)+25/27*sin(30*t+35/39)+5/18*sin(32*t+6/23)+11/29*sin(34*t+59/19)+23/33*sin(35*t+173/72)+16/31*sin(36*t+67/19)+9/31*sin(37*t+6/29)+7/25*sin(38*t+25/12)+19/31*sin(39*t+135/29)+21/53*sin(40*t+21/34)+1/14*sin(42*t+24/13)+17/32*sin(43*t+35/34)+27/43*sin(44*t+107/31)-9223/25)*theta(3*pi-t)*theta(t+pi))*theta(sqrt(sgn(sin(t/2))));
}
</script>

Modified http://d3js.org/d3.v3.min.js to a secure url

https://d3js.org/d3.v3.min.js