Description of The Result of Random Forests from sklearn

 

接下来是做随机森林,将参数导入,直接调用sklearn里面的RandomForestClassifier即可

df['species'] = pd.Categorical.from_codes(ydata, yname)
#print(df['species'])
df.head()
train, test = df[df['is_train']==True], df[df['is_train']==False]
features = df.columns[:100]
clf = RandomForestClassifier(n_jobs=2)

y, _ = pd.factorize(train['species'])
clf.fit(train[features], y)
preds = np.array(yname)[clf.predict(test[features])]
#print(preds)
pd.crosstab(test['species'], preds, rownames=['actual'], colnames=['preds'])

mmm = clf.feature_importances_
nnn = list(mmm)

nnn = [x*100 for x in nnn]
nnn = [float('%.5f' % x) for x in nnn]
print(nnn)

接下来是对数据的说明:

这是sklearn里面的举例数据集:一条xdata数据有四个值,对应一个y,格式是’numpy.ndarray’格式,但后来我替换成列表格式,不进行numpy转换,似乎也没有出现问题。所用到的数据有xdata\ xname\ ydata\ yname

{‘xdata’: array([[5.1, 3.5, 1.4, 0.2], [4.9, 3. , 1.4, 0.2], [4.7, 3.2, 1.3, 0.2], [4.6, 3.1, 1.5, 0.2], [5. , 3.6, 1.4, 0.2], [5.4, 3.9, 1.7, 0.4], [4.6, 3.4, 1.4, 0.3], [6. , 3. , 4.8, 1.8], [6.9, 3.1, 5.4, 2.1], [6.7, 3.1, 5.6, 2.4], …… [6.9, 3.1, 5.1, 2.3], [5.8, 2.7, 5.1, 1.9], [6.8, 3.2, 5.9, 2.3], [6.7, 3.3, 5.7, 2.5], [6.7, 3. , 5.2, 2.3], [6.3, 2.5, 5. , 1.9], [6.5, 3. , 5.2, 2. ], [6.2, 3.4, 5.4, 2.3], [5.9, 3. , 5.1, 1.8]]), ‘ydata’: array([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,……, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,……, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2]), ‘yname’: array([‘setosa’, ‘versicolor’, ‘virginica’], dtype=’<U10’), ‘xname’: [‘sepal length (cm)’, ‘sepal width (cm)’, ‘petal length (cm)’, ‘petal width (cm)’] ‘DESCR’: ‘Iris Plants Database\n====================\n\nNotes\n—–\nData Set Characteristics:\n :Number of Instances: 150 (50 in each of three classes)\n :Number of Attributes: 4 numeric, predictive attributes and the class\n :Attribute Information:\n - sepal length in cm\n - sepal width in cm\n - petal length in cm\n - petal width in cm\n - class:\n - Iris-Setosa\n - Iris-Versicolour\n - Iris-Virginica\n :Summary Statistics:\n\n ============== ==== ==== ======= ===== ====================\n Min Max Mean SD Class Correlation\n ============== ==== ==== ======= ===== ====================\n sepal length: 4.3 7.9 5.84 0.83 0.7826\n sepal width: 2.0 4.4 3.05 0.43 -0.4194\n petal length: 1.0 6.9 3.76 1.76 0.9490 (high!)\n petal width: 0.1 2.5 1.20 0.76 0.9565 (high!)\n ============== ==== ==== ======= ===== ====================\n\n :Missing Attribute Values: None\n :Class Distribution: 33.3% for each of 3 classes.\n :Creator: R.A. Fisher\n :Donor: Michael Marshall (MARSHALL%PLU@io.arc.nasa.gov)\n :Date: July, 1988\n\nThis is a copy of UCI ML iris datasets.\nhttp://archive.ics.uci.edu/ml/datasets/Iris\n\nThe famous Iris database, first used by Sir R.A Fisher\n\nThis is perhaps the best known database to be found in the\npattern recognition literature. Fisher's paper is a classic in the field and\nis referenced frequently to this day. (See Duda & Hart, for example.) The\ndata set contains 3 classes of 50 instances each, where each class refers to a\ntype of iris plant. One class is linearly separable from the other 2; the\nlatter are NOT linearly separable from each other.\n\nReferences\n———-\n - Fisher,R.A. “The use of multiple measurements in taxonomic problems”\n Annual Eugenics, 7, Part II, 179-188 (1936); also in “Contributions to\n Mathematical Statistics” (John Wiley, NY, 1950).\n - Duda,R.O., & Hart,P.E. (1973) Pattern Classification and Scene Analysis.\n (Q327.D83) John Wiley & Sons. ISBN 0-471-22361-1. See page 218.\n - Dasarathy, B.V. (1980) “Nosing Around the Neighborhood: A New System\n Structure and Classification Rule for Recognition in Partially Exposed\n Environments”. IEEE Transactions on Pattern Analysis and Machine\n Intelligence, Vol. PAMI-2, No. 1, 67-71.\n - Gates, G.W. (1972) “The Reduced Nearest Neighbor Rule”. IEEE Transactions\n on Information Theory, May 1972, 431-433.\n - See also: 1988 MLC Proceedings, 54-64. Cheeseman et al”s AUTOCLASS II\n conceptual clustering system finds 3 classes in the data.\n - Many, many more …\n’ }