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fabiovalse/README.md

Last active June 29, 2020 14:42
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Points Along an Archimedean Spiral
Raw
README.md
Raw
index.css
svg {
background: white;
}
.spiral {
fill: none;
stroke: #303030;
stroke-width: 3px;
}
Raw
index.html
<!DOCTYPE html>
<html>
<head>
<meta name="description" content="Points Along an Archimedean Spiral" />
<meta http-equiv="Content-Type" content="text/html;charset=utf-8">
<script type="text/javascript" src="http://d3js.org/d3.v2.js"></script>
</head>
<body>
<div id="chart"></div>
<script type="text/javascript" src="index.js"></script>
</body>
</html>
Raw
index.js
var width = 960,
height = 500;
var centerX = width/2,
centerY = height/2,
radius = 200,
sides = 200,
coils = 8,
rotation = 0;
// How far to step away from center for each side.
var awayStep = radius/sides;
// How far to rotate around center for each side.
var aroundStep = coils/sides;// 0 to 1 based.
// Convert aroundStep to radians.
var aroundRadians = aroundStep * 2 * Math.PI;
// Convert rotation to radians.
rotation *= 2 * Math.PI;
var new_time = [];
// For every side, step around and away from center.
for(var i=1; i<=sides; i++){
// How far away from center
var away = i * awayStep;
// How far around the center.
var around = i * aroundRadians + rotation;
// Convert 'around' and 'away' to X and Y.
var x = centerX + Math.cos(around) * away;
var y = centerY + Math.sin(around) * away;
new_time.push({x: x, y: y});
}
console.log(new_time);
var svg = d3.select("#chart").append("svg")
.attr("width", width)
.attr("height", height)
.append("g");
var lineFunction = d3.svg.line()
.x(function(d) { return d.x; })
.y(function(d) { return d.y; })
.interpolate("cardinal");
svg.append("path")
.attr("d", lineFunction(new_time))
.attr("stroke", "gray")
.attr("stroke-width", 0.5)
.attr("fill", "none");
var circles = svg.selectAll("circle")
.data(new_time)
.enter()
.append("circle")
.attr("cx", function (d) { return d.x; })
.attr("cy", function (d) { return d.y; })
.attr("r", 2);
@lonnietc
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Hello,

I am still learning how to use Javascript and 3D.js so here is a really simple question.

How can I add numbers, starting a 0, to each circle location?

I am also working on adding an interactive input and button that would allow you to dynamically adjust the number of rotations, and screen position, but now need to learn how to just add some integer numbers to each data point.

Thanks in advance.

@fabiovalse
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Author

Hi lonnietc, if you mean to add an SVG text containing an integer near every point on the spiral, you should change lines 56 to 62 to something like:

var circles = svg.selectAll("circle")
  .data(new_time);
circles.enter()
  .append("circle")
  .attr("cx", function (d) { return d.x; })
  .attr("cy", function (d) { return d.y; })
  .attr("r", 2);
circles.enter()
  .append("text")
  .attr("x", function (d) { return d.x; })
  .attr("y", function (d) { return d.y; })
  .text(function (d, i) { return i});

Of course, you should properly handle the visibility of your texts since in this way the visualization will result quite cluttered.

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