class_docstr: Class for averaging beat evaluation scores.
class_docstr_tok: ["Class","for","averaging","beat","evaluation","scores","."]
docstr: Error histogram.
docstr_tok: ["Error","histogram","."]
code: def error_histogram(self):
      """Error histogram."""
      if not self.eval_objects:
          # return an empty error histogram of length 0
          return np.zeros(0)
      # sum all error histograms to gather a global one
      return np.sum(
          [e.error_histogram for e in self.eval_objects], axis=0
      )
  
imports: from __future__ import absolute_import, division, print_function
  import warnings
  from functools import wraps
  import numpy
  from .None import MeanEvaluation, calc_absolute_errors, calc_errors, evaluation_io, find_closest_matches
  from .onsets import OnsetEvaluation
label_desc: Use image node_id 10 for calling the BeatMeanEvaluation obj's underlying member method code with example usage: obj.error_histogram() and returns: np, np