als-statistics/lib/table/simple-table/split.js

Modular JS statistics toolkit for Node.js and the browser: descriptive stats, correlations (Pearson/Spearman/Kendall), t-tests & ANOVA (Student/Welch), reliability (Cronbach’s alpha), regression (linear/logistic), clustering (DBSCAN/HDBSCAN), and table/co

export function split(colName, table, labels = {}) {
   const { columns, name, Table: { Statistics } } = table
   const col = columns[colName]
   if (!col) throw new Error(`Column ${colName} does not exist`)
   const statistics = new Statistics(`SplitedBy${colName}`)
   const groups = {}
   Object.entries(columns[colName].values).sort((a, b) => a[1] - b[1]).forEach(([i, v]) => {
      (groups[v] ? groups[v] : groups[v] = new Set()).add(Number(i))
   })
   for (let groupValue in groups) {
      const tName = labels[groupValue] || name + groupValue
      const newColumns = {}, indexes = groups[groupValue]
      for (let colName in columns) {
         newColumns[colName] = columns[colName].values.filter((v, i) => indexes.has(i))
      }
      statistics.addTable(newColumns, { name: tName })
   }
   return statistics
}