Given an angle and a radius, calculate a point's cartesian coordinates. See this StackExchange answer.
Last active
November 30, 2018 14:23
-
-
Save HarryStevens/9d2714bc1bf022e68afd05c78a09a9ee to your computer and use it in GitHub Desktop.
Cartesian Points In A Circle
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| license: gpl-3.0 |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| <!DOCTYPE html> | |
| <html> | |
| <head> | |
| <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> | |
| <style> | |
| body { | |
| margin: 0 auto; | |
| display: table; | |
| } | |
| text { | |
| text-anchor: middle; | |
| font-family: "Helvetica Neue", sans-serif; | |
| } | |
| .outline { | |
| fill: none; | |
| stroke: black; | |
| stroke-width: 2px; | |
| } | |
| .center { | |
| fill: tomato; | |
| } | |
| .circle { | |
| stroke-width: 2px; | |
| fill: none; | |
| } | |
| .line { | |
| stroke-width: 2px; | |
| } | |
| </style> | |
| </head> | |
| <body> | |
| <script src="https://d3js.org/d3.v5.min.js"></script> | |
| <script src="https://unpkg.com/[email protected]/build/geometric.js"></script> | |
| <script> | |
| var radius, | |
| margin = 2, | |
| dot_radius = 3, | |
| center_radius = 30, | |
| circles_data = []; | |
| var svg = d3.select("body").append("svg"); | |
| var g = svg.append("g") | |
| .attr("transform", "translate(" + margin + ", " + margin + ")"); | |
| var outline = g.append("circle") | |
| .attr("class", "outline"); | |
| var center = g.append("circle") | |
| .attr("class", "center") | |
| .attr("r", center_radius); | |
| var text = g.append("text").attr("dy", 5); | |
| window.onload = _ => { | |
| resize(); | |
| makeNewCircle(); | |
| redraw(); | |
| d3.interval(_ => { | |
| makeNewCircle(); | |
| redraw(); | |
| }, 500); | |
| window.onresize = resize; | |
| }; | |
| function resize(){ | |
| radius = Math.min(window.innerWidth, window.innerHeight) - margin * 2; | |
| d3.select("div").style("left", (window.innerWidth / 2) + "px").style("top", (radius / 2) + "px"); | |
| text.attr("x", radius / 2).attr("y", radius / 2) | |
| svg.attr("width", radius + margin * 2).attr("height", radius + margin * 2); | |
| outline | |
| .attr("r", radius / 2) | |
| .attr("cx", radius / 2) | |
| .attr("cy", radius / 2); | |
| center | |
| .attr("cx", radius / 2) | |
| .attr("cy", radius / 2); | |
| // Recalculate current points based on new radius. | |
| circles_data.forEach(d => { | |
| d.coordinates = geometric.translateDegrees([radius / 2, radius / 2], d.angle, d.distance_pct * radius / 200); | |
| return d; | |
| }); | |
| redraw(); | |
| } | |
| function redraw(){ | |
| var circles = g.selectAll(".circle") | |
| .data(circles_data, d => d.id); | |
| var lines = g.selectAll(".line") | |
| .data(circles_data, d => d.id); | |
| var dots = g.selectAll(".dot") | |
| .data(circles_data, d => d.id); | |
| circles | |
| .attr("cx", radius / 2) | |
| .attr("cy", radius / 2) | |
| .attr("r", d => radius * d.distance_pct / 200) | |
| .transition() | |
| .style("stroke", "#ccc") | |
| .style("opacity", .1); | |
| lines | |
| .attr("x1", radius / 2) | |
| .attr("y1", radius / 2) | |
| .attr("x2", d => d.coordinates[0]) | |
| .attr("y2", d => d.coordinates[1]) | |
| .transition() | |
| .style("opacity", .1); | |
| dots | |
| .attr("cx", d => d.coordinates[0]) | |
| .attr("cy", d => d.coordinates[1]) | |
| .transition() | |
| .style("opacity", .8); | |
| circles.enter().append("circle") | |
| .attr("class", "circle") | |
| .attr("r", d => radius * d.distance_pct / 200) | |
| .attr("cx", radius / 2) | |
| .attr("cy", radius / 2) | |
| .style("stroke", "steelblue") | |
| .style("opacity", 1e-6) | |
| .transition() | |
| .duration(250) | |
| .style("opacity", 1); | |
| lines.enter().append("line") | |
| .attr("class", "line") | |
| .attr("x1", radius / 2) | |
| .attr("y1", radius / 2) | |
| .attr("x2", radius / 2) | |
| .attr("y2", radius / 2) | |
| .style("stroke", "steelblue") | |
| .transition() | |
| .delay(125) | |
| .duration(250) | |
| .attr("x2", d => d.coordinates[0]) | |
| .attr("y2", d => d.coordinates[1]); | |
| dots.enter().append("circle") | |
| .attr("class", "dot") | |
| .attr("r", dot_radius) | |
| .attr("cx", d => d.coordinates[0]) | |
| .attr("cy", d => d.coordinates[1]) | |
| .attr("opacity", 1e-6) | |
| .transition() | |
| .delay(250) | |
| .duration(500) | |
| .attr("opacity", 1); | |
| center.raise(); | |
| text.raise(); | |
| } | |
| function makeNewCircle(distance, angle){ | |
| var new_obj = { | |
| distance_pct: Math.max((center_radius + dot_radius * 2) / radius * 100, randomPercent()), | |
| angle: randomAngle(), | |
| id: circles_data.length | |
| }; | |
| text.text(new_obj.angle); | |
| new_obj.coordinates = geometric.translateDegrees([radius / 2, radius / 2], new_obj.angle, new_obj.distance_pct * radius / 200) | |
| circles_data.push(new_obj); | |
| } | |
| function randomPercent(){ | |
| return randomBetween(0, 100); | |
| } | |
| function randomAngle(){ | |
| return randomBetween(0, 360); | |
| } | |
| function randomBetween(min, max){ | |
| return Math.floor(Math.random() * (max - min + 1) + min); | |
| } | |
| </script> | |
| </body> | |
| </html> |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment