`val ols : Core_bench.Measurement.t ‑> resp:Core_bench.Variable.t ‑> preds:Core_bench.Variable.t array ‑> float array Core.Or_error.t`
`val r_square : Core_bench.Measurement.t ‑> resp:Core_bench.Variable.t ‑> preds:Core_bench.Variable.t array ‑> coeffs:float array ‑> float`
`val bootstrap : trials:int ‑> Core_bench.Measurement.t ‑> resp:Core_bench.Variable.t ‑> preds:Core_bench.Variable.t array ‑> Core_bench.Analysis_result.Ci95.t array Core.Or_error.t`