code: def generate_observational_matrix(
      n,
      d,
      timelines,
      constant=False,
      independent=0,
      n_binary=0,
      model="aalen",
  ):
      hz, coeff, covariates = generate_hazard_rates(
          n, d, timelines, constant, independent, n_binary, model=model
      )
      R = generate_random_lifetimes(hz, timelines)
      covariates["event_at"] = R.T[0]
      return (
          covariates.sort_values(by="event_at"),
          pd.DataFrame(
              cumulative_integral(coeff.values, timelines),
              columns=coeff.columns,
              index=timelines,
          ),
      )
  
imports: import numpy
  import pandas
  from scipy import stats
  from scipy.optimize import newton
  from scipy.integrate import cumtrapz
label_desc: Use image node_id 14 for calling a global function with example usage: generate_observational_matrix(n, d, timelines, constant, independent, n_binary, model) and returns: covariates,  pd