Learn JS DataGetting Started (Learn JS Data)Reading in Data (Learn JS Data)Combining Data (Learn JS Data)Summarizing Data (Learn JS Data)Iterating Over and Reducing Data (Learn JS Data)Working with Strings (Learn JS Data)Regular Expressions (Learn JS Data)Working with Time (Learn JS Data)Checking Data Assumptions (Learn JS Data)
Grouping Data (Learn JS Data)
expenses = [
{ name: "jim", amount: 34, date: "11/12/2015" },
{ name: "carl", amount: 120.11, date: "11/12/2015" },
{ name: "jim", amount: 45, date: "12/01/2015" },
{ name: "stacy", amount: 12.00, date: "01/04/2016" },
{ name: "stacy", amount: 34.10, date: "01/04/2016" },
{ name: "stacy", amount: 44.80, date: "01/05/2016" }
]
expensesByName = d3.group(expenses, d => d.name)
expensesCount = d3.rollup(
expenses,
v => v.length, // aggregate the data by counting the number of items
d => d.name // group by name
)
expensesAvgAmount = d3.rollup(
expenses,
v => d3.mean(v, d => d.amount), // aggregate by the mean of amount
d => d.name // group by name
)
expenseMetrics = d3.rollup(
expenses,
v => ({
count: v.length,
total: d3.sum(v, d => d.amount),
avg: d3.mean(v, d => d.amount)
}),
d => d.name
)
expensesTotal = d3.rollups(
expenses,
v => ({
count: v.length,
total: d3.sum(v, d => d.amount),
avg: d3.mean(v, d => d.amount)
}),
d => d.name
)
expensesTotalByName = d3.rollup(
expenses,
v => d3.sum(v, d => d.amount), //Aggregate by the sum of amount
d => d.name, // group first by name
d => d.date // then by date
)
expensesTotalByDay = d3.rollup(
expenses,
v => d3.sum(v, d => d.amount), //Aggregate by the sum of amount
d => d.date, // now first by date
d => d.name // then by name
)
expensesByYear = d3.rollup(
expenses,
v => d3.sum(v, d => d.amount),
d => d.date.split("/")[2]
)
d3 = require('d3@6')
Purpose-built for displays of data
Observable is your go-to platform for exploring data and creating expressive data visualizations. Use reactive JavaScript notebooks for prototyping and a collaborative canvas for visual data exploration and dashboard creation.
