[[P1,P2],[P3,P4] ...]Correct rate Scoreneighbors.KNeighborsClassifier.score(X, y, sample_weight=None)We typically divide our training datasets into two categories, one for learning and training models, and one for testing, and this kinetic energy is the ability to test after learning to see the accuracy.Practical examplesFirst we take the example of film splitting in the KNN algorithm in the Machine learning series. We implemented a
1. What is k nearest neighbor
Popular Will, if I were a sample, the KNN algorithm would be to find a few recent samples, see what categories they all belong to, and then select the category with the largest percentage of their category. KNN is the full name of K-nearestneighbor,k is the number of samples we are looking for, k=1 is to find the most recent samples, and then their own category is the category
KNN (K Nearest Neighbor) for Machine Learning Based on scikit-learn package-complete example, scikit-learnknn
KNN (K Nearest Neighbor) for Machine Learning Based on scikit-learn package)
Scikit-learn (sklearn) is currently the most popular and powerful Python library for machine learning. It supports a wide range
Class, clustering, and regression analysis methods
Use sklearn for integration learning-practice, sklearn IntegrationSeries
Using sklearn for Integrated Learning-Theory
Using sklearn for Integrated Learning-Practice
Directory
1. Details about the parameters of Random Forest and Gradient Tree Boosting2. How to adjust parameters?2.1 adjustment objective: coordination
In sklearn, what kind of data does the classifier regression apply ?, Sklearn RegressionAuthor: anonymous userLink: https://www.zhihu.com/question/52992079/answer/156294774Source: zhihuCopyright belongs to the author. For commercial reprint, please contact the author for authorization. For non-commercial reprint, please indicate the source.
(Sklearn official guid
Sklearn database example-Decision Tree Classification and sklearn database example Decision-Making
Introduction of decision tree algorithm on Sklearn: http://scikit-learn.org/stable/modules/tree.html
1. Decision Tree: A non-parametric supervised learning method, mainly used for classification and regression. The goal of an algorithm is to create a model that pred
Tags: span tab important module IMG. SH oom amp DigitThere is data to be trained when doing machine learning, but fortunately Sklearn provides a number of well-labeled datasets for us to train.This section looks at what data sets are available for training in Sklearn. This data is located in Datasets, at the URL: http://scikit-learn.org/stable/modules/classes.html#module-sklearn.datasetsRoom Rate DataLoadin
A simple call to the decision tree method records1clf=Tree. Decisiontreeclassifier ()2datamat=[];labelmat=[]3Datapath='d:/machinelearning data/machinelearninginaction/ch05/testset.txt'4FR =Open (DataPath)5 forLineinchFr.readlines ():#readilnes () The contents of the file exist in the list6Linearr = Line.strip (). Split ()#Remove Spaces7Labelmat.append (int (linearr[-1]))8Datamat.append ([Float (linearr[0]), float (linearr[1])]) 9x=Np.array (Datamat)Teny=Np.array (Labelmat) One clf.fit (x, y) A
kissing number movie type California man 3 104 Romance He ' s not really into Dudes 2 romance Beautiful Woman 1 Bayi Romance Kevin Longblade 101 Action Robo Slay Er 5 action Amped II 98 2 Action unknown 18 90Unknown Task Description: Define the movie type by the number of fights and kisses to call Python's Sklearn module solver1.ImportNumPy as NP 2. fromSklearnImportNeighbors 3. KNN = neighbors. Kneighbors
1.
KNN principle:
There is a collection of sample data, also called a training sample set, and there is a label for each data in the sample set, that is, we know the correspondence between each data in the sample set and the owning category. After entering new data with no labels, each feature of the new data is compared with the characteristics of the data in the sample set, and the algorithm extracts the category labels of the most similar data (nea
Python machine learning-sklearn digging breast cancer cells (Bo Master personally recorded)Https://study.163.com/course/introduction.htm?courseId=1005269003utm_campaign=commissionutm_source= Cp-400000000398149utm_medium=shareCourse OverviewToby, a licensed financial company as a model validation expert, the largest data mining department in the domestic medical data center head! This course explains how to use Python's
KNN algorithm python implementation and simple digital recognition, knn algorithm python RecognitionAdvantages and disadvantages of kNN algorithm:
Advantages: high precision, insensitive to abnormal values, no input data assumptions
Disadvantage: both time complexity and space complexity are high.
Applicable data range: numeric and nominal
Algorithm ideas:
different algorithms, the concept of F1 value is put forward on the basis of precision and recall, and the overall evaluation of precision and recall is made. F1 is defined as follows:F1值 = 正确率 * 召回率 * 2 / (正确率 + 召回率)
Python Code implementation
It sklearn is easy to implement the above logic.
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from sklearn import neighbors, datasets, metricsimport
point.
#算法一 Call Method
#-*-encoding:utf-8-*-' in Sklearn calls
the method in Sklearn and uses its own data in Sklearn
@author: Ada
' '
print __doc__
import numpy as NP from
sklearn import neighbors,datasets
#下载数据
#64维 1797 Samples
Datas=datasets.load_digits ()
Totalnum=len (datas.data) #1797
#print totalnum
#print
] = Classcount.get (Voteilabel,0) +1#选择距离最小的k个点Sortedclasscount = sorted (Classcount.iteritems (), Key=operator.itemgetter (1), reverse=True)returnsortedclasscount[0][0]#排序 def createdataset():Group = Array ([[1.0,1.1],[1.0,1.0],[0,0],[0,0.1]]) labels = [' A ',' A ',' B ',' B ']returnGroup, Labelsgroup,labels=createdataset () classify0 ([0.5,0.5],group,labels,3)Output:‘B‘Case TWO:
Data Set IntroductionIris Iris DataSet, is a plant that is often used as a case of machine learning. There
()
plt.show ()
The image is then displayed as follows:3. Start experimenting with various regression methods
To speed up the test, a function is written that takes the object of a different regression class, and then it draws the image and gives the score.The functions are basically as follows:
def try_different_method (CLF):
clf.fit (x_train,y_train)
score = Clf.score (X_test, y_test)
result = Clf.predict (x_test)
plt.figure ()
Plt.plot (Np.arange (len (Result)), y_tes
of text (I., basic principle)R language Implementation ︱ local sensitive hashing algorithm (LSH) solves the problem of mechanical similarity of text (two, Textreuse introduction)Mechanical similarity python version of the four section:Lsh︱python realization of locally sensitive random projection forest--lshforest/sklearn (i.)Lsh︱python implementing a locally sensitive hash--lshash (ii)Similarity ︱PYTHON+OPENCV realization Phash algorithm +hamming dis
algorithm (LSH) solves the problem of mechanical similarity of text (I, basic principle)The R language implements the ︱ local sensitive hashing algorithm (LSH) to solve textual mechanical similarity problems (two. Textreuse introduction)The four parts of the mechanical-similar Python version:Lsh︱python realization of locally sensitive random projection forest--lshforest/sklearn (i.)Lsh︱python implementing a locally sensitive hash--lshash (ii)Similari
important aspects of the data.C.F.:SVD Singular value analysisIn practice, SVD singular value analysis will be used to replace it, because the PCA computational amount is larger.
From sklearn.decomposition import PCA
#从sklearn中导入PCA
PCA = PCA (n_components=0.8,whiten=true)
#设置PCA参数
#n_components:
#设为大于零的整数, will automatically select N main components,
#设为分数时, select the eigenvalues of the total eigenvalue is greater than n, as the principal component
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