code: def columns(self, dimensions=None):
          
          if dimensions is None:
              dimensions = self.kdims
          else:
              dimensions = [self.get_dimension(d, strict=True) for d in dimensions]
          vdims = [d for d in dimensions if d in self.vdims]
          if vdims:
              raise ValueError('%s element does not hold data for value '
                               'dimensions. Could not return data for %s '
                               'dimension(s).' %
                               (type(self).__name__, ', '.join([d.name for d in vdims])))
          return OrderedDict([(d.name, self.dimension_values(d)) for d in dimensions])
docs: Convert dimension values to a dictionary.
  
          Returns a dictionary of column arrays along each dimension
          of the element.
  
          Args:
              dimensions: Dimensions to return as columns
  
          Returns:
              Dictionary of arrays for each dimension