code: def oned():
      nsteps = 10000
      niter = 10
      nthreads = 2
  
      outfn = os.path.join(
          os.path.split(__file__)[0], "gauss_scaling.h5"
      )
      print(outfn)
      f = h5py.File(outfn, "w")
      f.create_dataset("data", (niter, 3), "f")
      f.close()
  
      pool = Pool(nthreads)
      pool.map(_worker, [(i, outfn, nsteps) for i in range(niter)])
  
      f = h5py.File(outfn)
      data = f["data"][...]
      f.close()
  
      pl.clf()
      pl.plot(data[:, 0], data[:, 1], "ks", alpha=0.5)
      pl.plot(data[:, 0], data[:, 2], ".k", alpha=0.5)
  
      pl.savefig(
          os.path.join(os.path.split(__file__)[0], "gauss_scaling.png")
      )
  
file_path: emcee/document/plots/oned.py
imports: import os
  import sys
  import time
  from multiprocessing import Pool
  import h5py
  import matplotlib.pyplot
  import numpy
  import emcee
label_desc: Use image node_id 4 for calling a global function with example usage: oned() without return types