Published
Edited
Apr 17, 2020
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md`# Line Chart from Scratch`
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height=200;
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styles = html`
<style>
svg{
background-color:#111;
}
.tick-major{
fill:#f00
}
</style>
`
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chart = {
const svg= d3.create('svg')
.attr('viewBox',[0,0,width,height]);
svg.append('g')
.call(xAxis);
svg.append('g')
.call(yAxis);
svg.append('path')
.datum(data)
.attr('fill','none')
.attr('stroke','#02d139')
.attr('stroke-width','3')
.attr('stroke-linejoin','round')
.attr('stroke-linecap','round')
.attr('d',line);
return svg.node();
}
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data=Object.assign(
(d3.csvParse(await FileAttachment("aapl.csv").text(), d3.autoType))
.map(
({date,close}) =>
({date,value:close})
)
, {yAxisName: "$ Close"}
)
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line=d3.line()
.defined( d => !isNaN(d.value))
.x(d => x(d.date))
.y(d => y(d.value))
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x=d3.scaleUtc()
.domain(d3.extent(data, d=> d.date))
.range([margin.left,width-margin.right])
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xAxis= g => g
.attr('transform',`translate(0,${height-margin.bottom})`)
.attr("color","steelblue")
.call(
d3.axisBottom(x).ticks(width/80).tickSizeOuter(0).tickSize(0))

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y=d3.scaleLinear()
.domain([0, d3.max(data, d=> d.value)]).nice()
.range([height - margin.bottom ,margin.top])
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yAxis= g => g
.attr('transform',`translate(${margin.left},0)`)
.attr("color","steelblue")
.call(d3.axisLeft(y).ticks(4).tickSize(-width+margin.left+margin.right))
.call(g => g.select(".domain").remove())
.call(g => g.select(".tick:last-of-type text").clone()
.attr("x", 3)
.attr("text-anchor", "start")
.attr("font-weight", "bold")
.text(data.yAxisName))
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margin = ({top: 20, right: 30, bottom: 30, left: 40})
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d3=require("d3@5")
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