Describe

Coral.Frame.describe is the first Frame feature that depends on published Nautilus. It currently targets pandas-style summary rows for numeric columns: count, mean, std, min, 25%, 50%, 75%, and max.

For float columns, NaN values are skipped before summary statistics are computed. The standard deviation follows pandas and uses sample ddof=1.

module Coral.BookDescribe
import Coral.Frame (from_pairs, describe, nrows, get_float_col, int_col_of_list)
export (main)
def main() -> f32 = {
  frame = from_pairs([("price", FloatCol(to_tensor([cast(10.0, f32), div(cast(0.0, f32), cast(0.0, f32)), cast(40.0, f32)]))), ("qty", int_col_of_list([cast(1, int64), cast(2, int64), cast(3, int64)]))])
  summary = describe(frame)
  add(cast(nrows(summary), f32), index(to_list(get_float_col(summary, "price")), cast(0, int64)))
}