謝謝user333700!
下面是你的提示的詳細說明。我生成一個3級分類變量數據,使用statsmodels共同擬合模型,然後測試分類變量的各個層面:
# 1. generate data
def rnorm(n,u,s):
return np.random.standard_normal(n)*s+u
a=rnorm(100,-1,1);
b=rnorm(100,0,1);
c=rnorm(100,+1,1);
n=rnorm(300,0,1); # some noise
y=np.concatenate((a,b,c))+n
g=np.zeros(300);
g[0:100]=1
g[100:200]=2
g[200:300]=3
df=pd.DataFrame({'Y':y,'G':g,'N':n});
# 2. fit model
r=smf.ols(formula="Y ~ N + C(G)",data=df).fit();
r.summary()
# 3. joint test
print r.params
A=np.identity(len(r.params)) # identity matrix with size = number of params
GroupTest=A[1:3,:] # for the categorical var., keep the corresponding rows of A
CovTest=A[3,:] # row for the continuous var.
print "Group effect test",r.f_test(GroupTest).fvalue
print "Covariate effect test",r.f_test(CovTest).fvalue
結果應該是這樣的:
Intercept -1.188975
C(G)[T.2.0] 1.315898
C(G)[T.3.0] 2.137431
N 0.922038
dtype: float64
Group effect test [[ 120.86097747]]
Covariate effect test [[ 259.34155851]]