swim = d3.rollups(rawSwimData.map(d => ({...d, distance: +d.event.split(" ")[0],
style: d.event.split(" ")[1], time: parseTimeString(d.time)})), d => {
return d[d3.minIndex(d, (v) => v.time )]
}, d => d.event, d => d.gender, d => d.olympics_year).map(([event, values]) => {
return values.map(([gender, years]) => {
return years.map(([year, data]) => {
return {event, gender, year, ...data}
})
})
}).flat(4)