import { scaleLinear, scaleTime, max, timeFormat, extent, histogram as bin, timeMonths, sum, brushX, select, event } from 'd3'; import { useRef, useEffect, useMemo } from 'react'; import { AxisBottom } from './AxisBottom'; import { AxisLeft } from './AxisLeft'; import { Marks } from './Marks'; const margin = { top: 0, right: 30, bottom: 20, left: 45 }; const xAxisLabelOffset = 54; const yAxisLabelOffset = 30; const xAxisTickFormat = timeFormat('%m/%d/%Y'); const xAxisLabel = 'Time'; const yValue = d => d['Total Dead and Missing']; const yAxisLabel = 'Total Dead and Missing'; export const DateHistogram = ({ data, width, height, setBrushExtent, xValue }) => { const innerHeight = height - margin.top - margin.bottom; const innerWidth = width - margin.left - margin.right; const xScale = useMemo( () => scaleTime() .domain(extent(data, xValue)) .range([0, innerWidth]) .nice(), [data, xValue, innerWidth] ); const binnedData = useMemo(() => { const [start, stop] = xScale.domain(); return bin() .value(xValue) .domain(xScale.domain()) .thresholds(timeMonths(start, stop))(data) .map(array => ({ y: sum(array, yValue), x0: array.x0, x1: array.x1 })); }, [xValue, yValue, xScale, data]); const yScale = useMemo( () => scaleLinear() .domain([0, max(binnedData, d => d.y)]) .range([innerHeight, 0]), [binnedData, innerHeight] ); const brushRef = useRef(); useEffect(() => { const brush = brushX().extent([[0, 0], [innerWidth, innerHeight]]); brush(select(brushRef.current)); brush.on('brush end', () => { setBrushExtent(event.selection && event.selection.map(xScale.invert)); }); }, [innerWidth, innerHeight]); return ( <> {yAxisLabel} {xAxisLabel} d} circleRadius={2} innerHeight={innerHeight} /> ); };

Migrant Deaths Linked Views with Brushing

Mila Frerichs