Published
Edited
Feb 9, 2022
dataFile = await FileAttachment("fake_app_download_rating.csv").text()
dataset = d3.csvParse(dataFile, (row) => ({
app_name: row.app_name,
downloads: parseInt(row.downloads),
average_rating: parseFloat(row.average_rating),
thirty_day_keep: parseFloat(row.thirty_day_keep)
}))
w = 600
h = dataset.length * 24
// our range is limited from 0 to width - 100,
// which is for the 80 pixels on left for axis and
// 20 pixels on right for padding
xScale = d3.scaleLinear()
.domain([0, d3.max(dataset, (d) => d.downloads)])
.rangeRound([0, w - 80 - 20]);
datasetAppNames = dataset.map((d) => d.app_name)
// using scale band to work with nominal values
// the Array.map() call allows us to get a new array
// by calling a function on each item of the source array
// here it pulls out the app_name
yScale = d3.scaleBand()
.domain(datasetAppNames)
.rangeRound([20, h - 20]);
// d3 allows scaling between colors
colorScale = d3.scaleLinear()
.domain([0, d3.max(dataset, (d) => d.downloads)])
.range(['#ccf', '#88d']);
makeChart1(dataset)
makeChart1 = (dataset) => {
// sort the data by downloads
// uses built-in Array.sort() with comparator function
dataset.sort((a,b) => b.downloads - a.downloads);
const chart = d3.create('svg')
.attr('width', w)
.attr('height', h);
chart.selectAll('rect')
.data(dataset)
.enter()
.append('rect')
.attr('x', 80)
.attr('y', (d) => yScale(d.app_name))
.attr('width', (d) => 0)
.attr('height', 20)
.attr('fill', '#88d')
.transition('displaydata')
.delay((d,i) => 35 * i)
.attr('width', (d) => xScale(d.downloads))
.attr('fill', (d) => colorScale(d.downloads))
.transition('staticfill')
.delay((d,i) => 35 * i)
.attr('fill', '#88d')
.transition('scaledfill')
.delay((d,i) => 35 * i)
.attr('fill', (d) => colorScale(d.downloads))
// AXES
chart.append('g')
.classed('axis', true)
.attr('transform', `translate(80, ${h - 20})`)
.call(d3.axisBottom(xScale));
chart.append('g')
.classed('axis', true)
.attr('transform', `translate(80,0)`)
.call(d3.axisLeft(yScale));
return chart.node()
}
d3 = require("d3@7")
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