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matrix inside circle
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| license: mit |
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.
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| <!DOCTYPE html> | |
| <head> | |
| <meta charset="utf-8"> | |
| <script src="https://d3js.org/d3.v4.min.js"></script> | |
| <style> | |
| body { | |
| margin: 50; | |
| } | |
| circle { | |
| fill: none; | |
| stroke: black; | |
| stroke-width: 2px; | |
| } | |
| rect { | |
| stroke: black; | |
| stroke-width: 1px; | |
| } | |
| </style> | |
| </head> | |
| <body> | |
| <div id="chart"></div> | |
| <div id="count"></div> | |
| <script> | |
| console.clear() | |
| let radius = 250 | |
| let diameter = radius * 2 | |
| let margin = 20 | |
| let squareWidth = 30 | |
| let n = Math.floor(diameter / squareWidth) | |
| let offset = (diameter - (n * squareWidth)) / 2 | |
| let width = diameter | |
| let height = width | |
| let numberOfSquaresInsideCircle = 0 | |
| let svg = d3.select("#chart").append("svg") | |
| .attr("width", width + (margin * 2)) | |
| .attr("height", height + (margin * 2)) | |
| let g = svg.append("g") | |
| .attr("transform", "translate(" + margin + ", " + margin + ")") | |
| for (var i = 0; i < n; i++) { | |
| for (var j = 0; j < n; j++) { | |
| let x = (i * squareWidth) + offset | |
| let y = (j * squareWidth) + offset | |
| let fill = "" | |
| // here i'm basing the square's colour on whether its in the circle | |
| // you could choose to not append the rect at all, or something similar | |
| if(isSquareOutsideCircle(x, y, squareWidth, radius)) { | |
| fill = "red" | |
| } else { | |
| fill = "grey" | |
| numberOfSquaresInsideCircle = numberOfSquaresInsideCircle + 1 | |
| } | |
| g.append("rect") | |
| .attr("x", x) | |
| .attr("y", y) | |
| .attr("width", squareWidth) | |
| .attr("height", squareWidth) | |
| .style("fill", fill) | |
| .attr("id", "cell-" + i + "-" + j) | |
| } | |
| } | |
| let squares = d3.selectAll("rect") | |
| let circle = g.append("circle") | |
| .attr("cx", radius) | |
| .attr("cy", radius) | |
| .attr("r", radius) | |
| console.log(numberOfSquaresInsideCircle) | |
| d3.select("#count") | |
| .text(numberOfSquaresInsideCircle) | |
| function isSquareOutsideCircle(squareX, squareY, squareW, circleR) { | |
| let outside1 = isPointOutsideCircle(squareX, squareY, circleR) | |
| let outside2 = isPointOutsideCircle((squareX + squareW), squareY, circleR) | |
| let outside3 = isPointOutsideCircle(squareX, (squareY + squareW), circleR) | |
| let outside4 = isPointOutsideCircle((squareX + squareW), (squareY + squareW), circleR) | |
| return outside1 | outside2 | outside3 | outside4 ? true : false | |
| } | |
| function isPointOutsideCircle(x, y, r) { | |
| return hypothenuese( | |
| Math.abs(r - x), | |
| Math.abs(r - y)) | |
| > | |
| r | |
| ? true : false | |
| } | |
| function hypothenuese(side1, side2) { | |
| return Math.sqrt((side1 * side1) + (side2 * side2)) | |
| } | |
| </script> | |
| </body> |
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