text: #!/usr/bin/env python3
  
  import loopfield as lf
  
  # create empty field with specified units
  field = lf.Field(length_units = lf.cm,
                   current_units = lf.A,
                   field_units = lf.uT)
  
  # single-turn 10 cm x-oriented coil at origin
  position = [0., 0., 0.]
  normal = [1., 0., 0.]
  radius = 10.
  current = 1.
  c = lf.Loop(position, normal, radius, current)
  
  # add loop to field
  field.addLoop(c);
  
  # evaluate vector field at origin
  B = field.evaluate([0., 0., 0.])
  print('B = ', B)
  
  # evaluate vector field 100 cm along axis
  B = field.evaluate([100., 0., 0.])
  print('B = ', B)
  
  # evaluate vector field on loop (infinite result)
  B = field.evaluate([0., radius, 0.])
  print('B = ', B)
  