I wrote couples of lines of codes to build up a mean-reverse model.
However, it shows:
21 Warning Undefined name 'rebalance'
21 Error Runtime exception: NameError: name 'rebalance' is not defined
23 Warning Undefined name 'record_vars'
41 Warning Undefined name 'raw'
Could anyone help or explain why these errors happen?
Thanks a lot!

def initialize(context):     

    context.security_list = [  
    sid(24),#Apple  
    sid(16841),#Amazon  
    sid(46632),#Google  
    sid(5061),#Microsoft  
    sid(11100),#Berkshire Hathaway B  
    sid(42950),#Facebook  
    sid(47740),#Alibaba  
    sid(39062),#JPMorgan Chase  
    sid(4151),#Johnson & Johnson  
    sid(35920),#Visa  
    sid(8347),#ExxonMobil  
    sid(8229),#Walmart  
    sid(5938),#Procter & Gamble  
    sid(32146),#Mastercard  
    sid(52320)#AT&T Inc  
]   

schedule_function(rebalance,date_rules.week_start(),time_rules.market_open())  
schedule_function(record_vars,date_rules.every_day(),time_rules.market_close())  
def compute_weights(context,data):  
    hist = data.history(context.security_list, "price", 30, "ld")  
    prices_10 = hist[-10:]  
    prices_30 = hist[-30:]  
    sma_10 = prices_10.mean()  
    sma_30 = prices_30.mean()  
    raw_weights = (sma_10 - sma_30) / sma_30  
    normalized_weights = raw_weights / raw_weights.abs().sum()

    return normalized_weights  
def rebalance(context, data):  
    weights = compute_weights(context, data)  
    for security in context.security_list:  
        if data.can_trade(security):  
            order_target_percent(security, weights[security])  
def record_vars(context, data):  
    longs = shorts = 0  
    for position in context.portfolio.positions.itervalues():  
        if position.amount > 0:  
            longs += 1  
        elif position.amount < 0:  
            shorts += 1  
    record(leverage=context.account.leverage, long_count = longs,  
           short_count = shorts)