docstr: Variations on the constructors in the Elements notebook
docstr_tok: ["Variations","on","the","constructors","in","the","Elements","notebook"]
code: def setUp(self):
      "Variations on the constructors in the Elements notebook"
  
      np.random.seed(1)
      frequencies1, edges1 = np.histogram(
          [np.random.normal() for i in range(1000)], 20
      )
      self.hist1 = Histogram((edges1, frequencies1))
      np.random.seed(2)
      frequencies2, edges2 = np.histogram(
          [np.random.normal() for i in range(1000)], 20
      )
      self.hist2 = Histogram((edges2, frequencies2))
      self.hist3 = Histogram((edges2, frequencies1))
      self.hist4 = Histogram((edges1, frequencies2))
  
imports: import numpy
  from holoviews import Bars, Curve, Dimension, Histogram, Points, Scatter, VectorField
  from holoviews.element.comparison import ComparisonTestCase
label_desc: Use image node_id 1 for calling the HistogramComparisonTest obj's underlying member method code with example usage: obj.setUp() without return types