@jrc03c/js-math-tools/src/series/series-get-subset-by-indices.mjs

some math tools for JS

import { assert } from "../assert.mjs"
import { forEach } from "../for-each.mjs"
import { isArray } from "../is-array.mjs"
import { isUndefined } from "../is-undefined.mjs"
import { isWholeNumber } from "../helpers/is-whole-number.mjs"
import { map } from "../map.mjs"
import { range } from "../range.mjs"
import { shape } from "../shape.mjs"

function seriesGetSubsetByIndices(series, indices) {
  const dataShape = series.shape

  if (isUndefined(indices)) indices = range(0, dataShape[0]).toArray()

  assert(
    isArray(indices),
    "The `indices` array must be 1-dimensional array of whole numbers.",
  )

  assert(
    shape(indices).length === 1,
    "The `indices` array must be a 1-dimensional array of whole numbers.",
  )

  assert(
    indices.length > 0,
    "The `indices` array must contain at least one index.",
  )

  forEach(indices, index => {
    assert(
      isWholeNumber(index),
      "The `indices` array must be a 1-dimensional array of whole numbers.",
    )

    assert(
      index < series.index.length,
      `The row index ${index} is out of bounds.`,
    )
  })

  const rows = map(indices, i => series.index[i])
  return series.getSubsetByNames(rows)
}

export { seriesGetSubsetByIndices }