コード例 #1
0
ファイル: linear.py プロジェクト: purepu/recsys
def gen_func(u, v):
    '''R(v) = a + b * R(u)'''
    # cache layer
    try:
        a, b = conn.execute('SELECT a, b FROM core_func WHERE id = %d' % (u * (N_USERS + 1) + v)).fetchone() 
        return lambda x: a + b * x
    except:
        pass
    # unsuccessful hit
    I = corate(u, v)
    ru = get_ratings(u, I)
    rv = get_ratings(v, I)
    return _gen_func(ru, rv)
コード例 #2
0
ファイル: linear.py プロジェクト: purepu/recsys
def cache(init = False):
    '''caching function parameters -- a and b in R(v) = a + b * R(u)'''
    if init:
        conn.execute('DELETE FROM core_func')
    x = conn.execute('SELECT MAX(id) FROM core_func').fetchone()[0] / (N_USERS + 1)
    for i in range(x + 1, N_USERS + 1):
        for j in range(1, N_USERS + 1):
            try:
                I = corate(i, j)
                ru, rv = array(get_ratings(i, I)), array(get_ratings(j, I))
                fp = lambda x, p: p[0] + p[1] * x
                e = lambda p, y, x: abs(fp(x, p) - y).sum()
                p = fmin(e, array([0, 1]), args = (rv, ru), maxiter = 10000, maxfun = 10000, disp = 0)
                a, b = p[0], p[1]
                conn.execute('INSERT INTO core_func VALUES(%d, %lf, %lf)' % (i * (N_USERS + 1) + j, a, b))
            except sqlite3.IntegrityError:
                print 'chongfu!'
        print i
        conn.commit()