class_docstr: Bar graph class
docstr: Compute y min and max and y scale and set labels
code: def _compute(self):
      """Compute y min and max and y scale and set labels"""
      if self._min:
          self._box.ymin = min(self._min, self.zero)
      if self._max:
          self._box.ymax = max(self._max, self.zero)
      self._x_pos = (
          [x / self._len for x in range(self._len + 1)]
          if self._len > 1
          else [0, 1]
      )  # Center if only one value
  
      self._points(self._x_pos)
  
      self._x_pos = [(i + 0.5) / self._len for i in range(self._len)]
  
file_path: pygal/pygal/graph/bar.py
imports: from pygal.graph.graph import Graph
  from pygal.util import alter, decorate, ident, swap
label_desc: Use image node_id 4 for calling the Bar obj's underlying member method code with example usage: obj._compute() without return types