Principal Web Developer at Freedom of the Press Foundation
Beantown Stomp 2023 CO₂ LevelsAssorted CO₂ ReadingsNYC SARS-CoV-2 Wastewater DataAranet4 Data UtilitiesFreedom of the Press Foundation 2022 All Staff CO₂ LevelsCO₂ Measurements for ESCape at Pinewoods Camp 2022Boston-Area SARS-CoV-2 Wastewater LevelsCharting a Case Fatality Rate by WaveCharting a Moving Case Fatality RateWhich states’ worst pandemic days were this week?Covid Cases vs. Deaths and HospitalizationsMassachusetts COVID DataMassachusetts Coronavirus Cases by TownCOVID-19 Infection and Fatality by RaceWhere is COVID-19 rising and falling in the U.S.?How many SARS-CoV-2 tests are we running in the U.S.?
U.S. Air Travel in a Pandemic
data = {
let finished = false
let output = []
let fetchUrl = CORS_PROXY + INITIAL_URL
const domparser = new DOMParser()
const dateParser = d3.timeParse('%-m/%-d/%Y')
while (!finished){
// Fetch the HTML document and parse it
const rawHtml = await (await fetch(fetchUrl)).text()
const htmlDoc = domparser.parseFromString(rawHtml, 'text/html')
// Parse rows from the table into object form
const rows = Array.from(htmlDoc.querySelectorAll('.views-table tbody tr')).map(row => ({
date: dateParser(row.querySelector('.views-field-field-today-date').innerHTML.trim()),
thisYear: parseInt(
row.querySelector('.views-field-field-this-year').innerHTML.trim().replace(/,/g,''),
10
),
lastYear: parseInt(
row.querySelector('.views-field-field-last-year').innerHTML.trim().replace(/,/g,''),
10
)
}))
output = output.concat(rows)
// If next link exists, swipe the querystring and append it to the initial URL to
// paginate to the next page. Otherwise, terminate the loop
const nextLink = htmlDoc.querySelector('.pager__link--next')
if (nextLink !== null) {
fetchUrl = CORS_PROXY + INITIAL_URL + '?' + nextLink.href.split('?')[1]
} else {
finished = true
}
}
// If we get exactly 200 rows, only the first page of data loaded, most likely
if (output.length === 200) throw('Data failed to completely load. Try refreshing.')
return output
}
averageLine = vl.markLine()
.encode(
vl.opacity().value('1'),
vl.x().fieldT('date').title(null),
vl.y().fieldQ('average').axis({ format: '.2s' }).title('Travelers'),
vl.color().fieldN('year').title('Year'),
)
travelerPoints = vl.markPoint({ filled: true })
.encode(
vl.opacity().value('0.35'),
vl.x().fieldT('date').title(null),
vl.y().fieldQ('travelers').title('Travelers'),
vl.color().fieldN('year').title('Year')
)
comparisonChart = vl.layer(averageLine, travelerPoints)
.data(data)
.transform(
vl.fold(['thisYear', 'lastYear']).as(['year', 'travelers']),
vl.calculate('datum.year === "thisYear" ? 2020 : 2019').as('year'),
vl.window(vl.average('travelers').as('average'))
.sort(
vl.fieldT('date'),
vl.order('ascending')
)
.groupby('year')
.frame([-6, 0])
)
.title('Travelers passing through TSA checkpoints 2020 and 2019')
.width(width * 0.8)
.height(width * 0.8 * 0.333)
percentAverageLine = vl.markLine()
.encode(
vl.color().value('#0C8'),
vl.x().fieldT('date').title(null),
vl.y().fieldQ('percentageAverage').title('Percentage of Baseline')
)
percentPoints = vl.markPoint({ filled: true })
.encode(
vl.opacity().value('0.35'),
vl.color().value('#0C8'),
vl.x().fieldT('date').title(null),
vl.y().fieldQ('percentage').axis({ format: '.0%' }).title('Percentage of Baseline')
)
percentageChart = vl.layer(percentAverageLine, percentPoints)
.data(data)
.transform(
vl.calculate('datum.thisYear / datum.lastYear').as('percentage'),
vl.window(vl.average('percentage').as('percentageAverage'))
.sort(vl.fieldT('date'), vl.order('ascending'))
.frame([-6, 0])
)
.title('2020 travelers compared to 2019 baseline')
.width(width * 0.8)
.height(width * 0.8 * 0.333)
html`
<style type="text/css">
/* make charts responsive */
svg.marks {
width: 100% !important;
height: auto !important;
}
</style>
`
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