jacobtfisher · July 11, 2020 16:25
diff --git a/README.md b/README.md
diff --git a/index.html b/index.html
 <!DOCTYPE html>
 <html>
 <head>
    <title>Viridis Palette Generator</title>
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/normalize/6.0.0/normalize.min.css" />
    <style>
        body {
            max-width: 800px;
            margin: 0 auto;
        }
        p {
            font-height: 1rem;
            line-height: 1.3rem;
        }
        input {
            width: 50px;
        }
        #preview {
            width: 270px;
            height: 10px;
            margin-top: 10px;
        }
        #levels {
            margin-top: 20px;
        }
        div.level {
            width: 100%; 
            height: 75px;
            display: block;
            margin-bottom: 1rem;
        }
        div.level div {
            display: inline-block;
        }
        div.block {
            height: 100%;
            width: 75px;
        }
    </style>
 </head>
 <body style="font-family: sans-serif;">

 <h1>Viridis Color Palette Generator</h1>
 <p>
    The <a href="http://bids.github.io/colormap/">matplotlib colormaps</a> introduced in 2015 are widely popular, with implementations of the palettes in <a href="https://cran.r-project.org/web/packages/viridis/vignettes/intro-to-viridis.html">R</a>, <a href="https://github.com/d3/d3-scale#interpolateViridis">D3js</a>, and others. Popular for good reason, the palettes are colorblind-friendly, retain representational clarity in greyscale, and are generally aesthetically pleasing.
 </p>
 <p>
    This tool provides a convenience wrapper around D3js's viridis implementation for use in data visualization tools with manual color value specification (e.g., Microsoft Excel, ArcGIS, and Tableau to name a few). To begin, select the number of categories and the color palette you'd like to use. 
 </p>

 <label for="groups">Categories: </label>
 <input type="number" id="groups" value="5" min="2" max="256">
 <label for="palette">Palette: </label>
 <select name="palette" id="palette">
    <option value="v">viridis</option>
    <option value="i">inferno</option>
    <option value="m">magma</option>
    <option value="p">plasma</option>
 </select>
 <!-- <button id="generate">Generate</button> -->
 <div id="preview"></div>

 <div id="levels"></div>

 <script src="https://d3js.org/d3.v4.min.js"></script>
 <script>
    d3.select('input').on('change', function() {
        generatePalette();
    });
    d3.select('input').on('keyup', function() {
        generatePalette();
    });
    d3.select('select').on('change', function() {
        generatePalette();
    });
    function generatePalette() {
        var n = parseInt(d3.select("#groups").property("value"));
        if (n > 256) {
            n = 256;
            d3.select("#groups").property("value", 256);
        }
        var p = d3.select("#palette").property("value");

        // Interpolation Scale Proxy
        var paletteProxy = function(_l) {
            switch (p) {
                case "v":
                    return d3.interpolateViridis(_l);
                case "i":
                    return d3.interpolateInferno(_l);
                case "m":
                    return d3.interpolateMagma(_l);
                case "p":
                    return d3.interpolatePlasma(_l);
                default:
                    break;
            }
        };

        // Update the preview
        var gradient = "linear-gradient(to right, " +
                       paletteProxy(1.0) + ", " +
                       paletteProxy(0.5) + ", " +
                       paletteProxy(0.0) + "" +
                       ")";
        d3.select("#preview").style("background", gradient);
        d3.select("#preview").style("background", gradient);

        // Update the value-levels
        var data = [];
        d3.range(0, 1 + 1/(n - 1), 1/(n - 1))
            .slice(0, n)
            .reverse()
            .map(function(l) {
                var r, g, b, hex;
                hex = paletteProxy(l);
                r = parseInt(hex.slice(1, 3), 16);
                g = parseInt(hex.slice(3, 5), 16);
                b = parseInt(hex.slice(5, 7), 16);
                var obj = {
                    "background": hex,
                    "rgb": [r, g, b]
                };
                data.push(obj);
            });
        d3.select("#levels")
            .html("")
            .selectAll("div")
            .data(data).enter()
            .append("div")
            .classed("level", true)
                .append("div")
                .classed("block", true)
                .style("background-color", function(d) {return d.background;})
                .select(function() {return this.parentNode})
                .append("div")
                    .html(function(d){
                        var rgb = "rgb(" + d.rgb.join(", ") + ")";
                        var hex = d.background;
                        return rgb + "<br><br>" + hex}
                    )
                    .style("position", "absolute")
                    .style("padding-top", "1rem")
                    .style("padding-left", "1rem");

    }
 </script>
 <script type="text/javascript">
        generatePalette();
 </script>
 </body>
 </html>
	<!DOCTYPE html>
	<html>
	<head>
	<title>Viridis Palette Generator</title>
	<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/normalize/6.0.0/normalize.min.css" />
	<style>
	body {
	max-width: 800px;
	margin: 0 auto;
	}
	p {
	font-height: 1rem;
	line-height: 1.3rem;
	}
	input {
	width: 50px;
	}
	#preview {
	width: 270px;
	height: 10px;
	margin-top: 10px;
	}
	#levels {
	margin-top: 20px;
	}
	div.level {
	width: 100%;
	height: 75px;
	display: block;
	margin-bottom: 1rem;
	}
	div.level div {
	display: inline-block;
	}
	div.block {
	height: 100%;
	width: 75px;
	}
	</style>
	</head>
	<body style="font-family: sans-serif;">

	<h1>Viridis Color Palette Generator</h1>
	<p>
	The <a href="http://bids.github.io/colormap/">matplotlib colormaps</a> introduced in 2015 are widely popular, with implementations of the palettes in <a href="https://cran.r-project.org/web/packages/viridis/vignettes/intro-to-viridis.html">R</a>, <a href="https://github.com/d3/d3-scale#interpolateViridis">D3js</a>, and others. Popular for good reason, the palettes are colorblind-friendly, retain representational clarity in greyscale, and are generally aesthetically pleasing.
	</p>
	<p>
	This tool provides a convenience wrapper around D3js's viridis implementation for use in data visualization tools with manual color value specification (e.g., Microsoft Excel, ArcGIS, and Tableau to name a few). To begin, select the number of categories and the color palette you'd like to use.
	</p>

	<label for="groups">Categories: </label>
	<input type="number" id="groups" value="5" min="2" max="256">
	<label for="palette">Palette: </label>
	<select name="palette" id="palette">
	<option value="v">viridis</option>
	<option value="i">inferno</option>
	<option value="m">magma</option>
	<option value="p">plasma</option>
	</select>
	<!-- <button id="generate">Generate</button> -->
	<div id="preview"></div>

	<div id="levels"></div>

	<script src="https://d3js.org/d3.v4.min.js"></script>
	<script>
	d3.select('input').on('change', function() {
	generatePalette();
	});
	d3.select('input').on('keyup', function() {
	generatePalette();
	});
	d3.select('select').on('change', function() {
	generatePalette();
	});
	function generatePalette() {
	var n = parseInt(d3.select("#groups").property("value"));
	if (n > 256) {
	n = 256;
	d3.select("#groups").property("value", 256);
	}
	var p = d3.select("#palette").property("value");

	// Interpolation Scale Proxy
	var paletteProxy = function(_l) {
	switch (p) {
	case "v":
	return d3.interpolateViridis(_l);
	case "i":
	return d3.interpolateInferno(_l);
	case "m":
	return d3.interpolateMagma(_l);
	case "p":
	return d3.interpolatePlasma(_l);
	default:
	break;
	}
	};

	// Update the preview
	var gradient = "linear-gradient(to right, " +
	paletteProxy(1.0) + ", " +
	paletteProxy(0.5) + ", " +
	paletteProxy(0.0) + "" +
	")";
	d3.select("#preview").style("background", gradient);
	d3.select("#preview").style("background", gradient);

	// Update the value-levels
	var data = [];
	d3.range(0, 1 + 1/(n - 1), 1/(n - 1))
	.slice(0, n)
	.reverse()
	.map(function(l) {
	var r, g, b, hex;
	hex = paletteProxy(l);
	r = parseInt(hex.slice(1, 3), 16);
	g = parseInt(hex.slice(3, 5), 16);
	b = parseInt(hex.slice(5, 7), 16);
	var obj = {
	"background": hex,
	"rgb": [r, g, b]
	};
	data.push(obj);
	});
	d3.select("#levels")
	.html("")
	.selectAll("div")
	.data(data).enter()
	.append("div")
	.classed("level", true)
	.append("div")
	.classed("block", true)
	.style("background-color", function(d) {return d.background;})
	.select(function() {return this.parentNode})
	.append("div")
	.html(function(d){
	var rgb = "rgb(" + d.rgb.join(", ") + ")";
	var hex = d.background;
	return rgb + "<br><br>" + hex}
	)
	.style("position", "absolute")
	.style("padding-top", "1rem")
	.style("padding-left", "1rem");

	}
	</script>
	<script type="text/javascript">
	generatePalette();
	</script>
	</body>
	</html>