def demo():
    """demo is used to demonstrate typical examples about this class."""
    demostr = """
import clubear as cb
import numpy as np
#clubear.csv is generated by cb.manager.demo()
pm=cb.pump('clubear.csv')  #read in the demodata for illustration
pm.drop=['brand','company','weight'] #drop some varialbe for illustration
pm.qlist=['age','height','logsales','price'] #define the quant variables
ck=cb.check(pm).table(tv=True); #levels of quali variables

tk=cb.tank(pm); #create a new tank to hold the pump work for prepressing
tk.app(np.log,'age','logage') #app np.log transformation to age
tk.app(lambda x: x**2,'height') #app a user defined func to height
tk.ady('gender',['Female']) #add dummy for gender
tk.ady('region',ck['region'][1]) #add dummy for region
ck=cb.check(tk).stats() #check the newly generated tank        
"""
    print(demostr)
