udacity python machine learning

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Software--machine learning and Python, clustering, K--means

Citycluster[label[i]].append (Cityname[i]) #将每个簇的城市输出For I in range (len (citycluster)):Print ("expenses:%.2f"% expenses[i]) #将每个簇的平均花费输出Print (Citycluster[i])Click to run, you can come out results.Where the N_clusters class, the consumption level of similar cities gathered in a classExpense: The numerical plus of the central point of the cluster, that is, the average consumption levelImplementation process:1, establish the project, import Sklearn related packageImport NumPy as NPFrom Sklearn.cl

NBC naive Bayesian classifier ———— machine learning actual combat python code

)]=1 else:print "The word:%s is not in my vocabulary!" %word return returnvecdef TRAINNBC (trainsamples,traincategory): Numtrainsamp=len (Trainsamples) NumWords=len (train Samples[0]) pabusive=sum (traincategory)/float (numtrainsamp) #y =1 or 0 feature Count P0num=np.ones (numwords) P1NUM=NP.O NES (numwords) #y =1 or 0 category count P0numtotal=numwords p1numtotal=numwords for I in Range (Numtrainsamp): if Traincategory[i]==1:p0num+=trainsamples[i] P0numtotal+=sum (Trainsamples[i]) E

Python vs machine learning-data preprocessing

attribute in the data set. The general situation is somewhere between the two.D. High-dimensional mappingMap properties to high-dimensional space. This is the most precise approach, which completely retains all the information and does not add any additional information. For example, Google, Baidu's CTR Prediction model, pre-processing will be all the variables to deal with this, up to hundreds of millions of dimensions. The benefit of this is that the entire information of the original data is

The linear regression of Python machine learning

=linearr.predict (X_train) #基于训练集得到的线性y值Plt.figure ()Plt.scatter (x_train,y_train,color= ' green ') #原始训练集数据散点图Plt.plot (x_train,y_train_pred,color= ' black ', linewidth=4) #线性回归的拟合线Plt.title (' Train ') #标题Plt.show ()Y_test_pred=linearr.predict (X_test)Plt.scatter (x_test,y_test,color= ' green ') #绘制测试集数据散点图Plt.plot (x_test,y_test_pred,color= ' black ', linewidth=4) #基于线性回归的预测线Plt.title (' Test ')Plt.show ()Print (' mse= ', Sm.mean_squared_error (y_test,y_test_pred)) #MSE值Print (' r2= ', Sm.r2_

Python numpy machine Learning Library Use example

Installation sudo yum install NumPy From numpy Import * Produces an array Random.rand (4,5) Result Array ([[0.79056842, 0.31659893, 0.34054779, 0.97328131, 0.32648329], [0.51585845, 0.70683055, 0.31476985, 0.07952725, 0.80907845], [0.81623517, 0.61038487, 0.66679161, 0.77412742, 0.03394483], [0.41758993, 0.54425978, 0.65350633, 0.90397197, 0.72706079]]) Produce a matrix >>> Randmat=mat (Random.rand (bis)) >>> randmat.i Matrix ([[[1.72265179, 0.82071484, 0.8218207,-3.20005387], [0.60602642,-1.28

Machine learning Path: Python naive Bayesian classifier Predictive news category

Misc.forsale 0.91 0.70 0.79 257 the Rec.autos 0.89 0.89 0.89 238 - Rec.motorcycles 0.98 0.92 0.95 276 - Rec.sport.baseball 0.98 0.91 0.95 251 the Rec.sport.hockey 0.93 0.99 0.96 233 the Sci.crypt 0.86 0.98 0.91 238 the sci.electronics 0.85 0.88 0.86 249 the sci.med 0.92 0.94 0.93 245 - sci.space 0.89 0.96 0.92 221 the Soc.religion.christian 0.78 0.96 0.86 232 the talk.politics.guns 0.88 0.96 0.92 251 the talk.politics.mideast 0.90 0.98 0.94 23194 Talk.politics.misc 0.79 0.89 0.84 188 the Talk.r

The way of the rookie--nonlinear regression of machine learning personal understanding and Python implementation

:", X) - Print("Y:", Y) - innumiterations=100000 -alpha=0.0005 toTheta=np.ones (x.shape[1]) +Theta=graientdescent (x,y,theta,alpha,x.shape[0],numiterations) - Print(Theta)Operation Result:...... Too many output data to intercept only the next more than 10 linesIteration 99988/cost:3.930135Iteration 99989/cost:3.930135Iteration 99990/cost:3.930135Iteration 99991/cost:3.930135Iteration 99992/cost:3.930135Iteration 99993/cost:3.930135Iteration 99994/cost:3.930135Iteration 99995/cost:3.930135Iterat

Machine learning python combat----linear regression

* (XMAT.T * (Weights *Ymat)) returnTestPoint *SigmadefLwlrtest (Testarr,xarr,yarr,k = 1.0): M=shape (Testarr) [0] Yhat=zeros (m) forIinchRange (m): Yhat[i]=LWLR (testarr[i],xarr,yarr,k)returnYhatThe LWLR () function is the code for locally weighted linear regression, and the function of the lwlrtest () function is to make the LWLR () function traverse the entire data set. We also need to draw a picture to see how the results fit. def PlotLine1 (testarr,xarr,yarr,k = 1.0 = Mat (Xarr) ymat = Ma

Machine learning Path: Python K-mean clustering Kmeans handwritten numerals

Python3 Learning using the APIUsing the data set on the Internet, I downloaded him to a localcan download datasets in my git: https://github.com/linyi0604/MachineLearningCode:1 ImportNumPy as NP2 ImportPandas as PD3 fromSklearn.clusterImportKmeans4 fromSklearnImportMetrics5 6 " "7 K-Mean-value algorithm:8 1 randomly selected K samples as the center of the K category9 2 from the K sample, select the nearest sample to be the same category as yourself,

A classical algorithm for machine learning and python implementation---naive Bayesian classification and its application in text categorization and spam detection

called the polynomial model, but its class conditional probability calculation formula is not accurate.Referencesalgorithm Grocer--naive Bayesian classification of classification algorithm (Naive Bayesian classification)study of naive Bayesian text classification algorithmThe author of this paper, Adan, derives from: The classical algorithm of machine learning and the implementation of

"Dawn Pass number ==> machine learning Express" model article 05--naive Bayesian "Naive Bayes" (with Python code)

, or K nearest neighbor (Knn,k-nearestneighbor) classification algorithm, is one of the simplest methods in data mining classification technology. The so-called K nearest neighbor is the meaning of K's closest neighbour, saying that each sample can be represented by its nearest K-neighbor.The core idea of the KNN algorithm is that if the majority of the k nearest samples in a feature space belong to a category, the sample also falls into this category and has the characteristics of the sample on

Python Machine Learning Library Sciki-earn Practice

!accuracy:87.07%******************* SVM ********************Training took3831. 564000s!accuracy:94.35%******************* GBDT ********************In this data set, because the cluster of data distribution is better (if you understand this database, see its T-sne map can be seen.) Since the task is simple, it has been considered a toy dataset in the deep learning boundary, so KNN has a good effect. GBDT is a very good algorithm, in Kaggle and other bi

Machine learning Path: Python dictionary feature extractor Dictvectorizer

Python3 Learning using the APIA sample of a data structure of a dictionary type, extracting features and converting them into vector formSOURCE Git:https://github.com/linyi0604/machinelearningCode:1 fromSklearn.feature_extractionImportDictvectorizer2 3 " "4 dictionary feature Extractor:5 pumping and vectorization of dictionary data Structures6 category type features vectorization with 0 12 values using prototype feature names7 numeric type features r

Machine learning notes about Python implementation Kmean algorithm

()--------------------------------------------------------------------------------------------------------------- ---------------------------------------At lastCode SummaryImport NumPy as Npimport cv2from matplotlib import pyplot as PltX = Np.random.randint (25,50, (25,2)) Y = Np.random.randint (6 0,85, (25,2)) Z = Np.vstack ((x, y)) # Convert to np.float32z = Np.float32 (Z) plt.hist (z,100,[0,100]), Plt.show () # define Criteria and apply Kmeans () criteria = (CV2. Term_criteria_eps + CV2. Ter

Machine learning in coding (Python): Use greedy search "for feature selection"

Print "Performing greedy feature selection ..." score_hist = []n = 10good_features = Set ([]) # greedy Feature selection LOOPW Hile Len (score_hist) if f not in good_features: feats = List (good_features) + [f] Xt = Sparse.hstack ([xts[j] for J in feats]). TOCSR () C5/>score = Cv_loop (Xt, y, model, N) Scores.append ((score, F)) print "Feature:%i Mean AUC:%f"% (f, score) g Ood_features.add (sorted (scores) [ -1][1]) Score_hist.append (sorted

Machine learning in coding (Python): Merge feature by keyword, delete useless feature, convert to NumPy array

=true) # drop useless columns and create LABELSIDX = test.id.values.astype (int) test = Test.drop ([' id ', ' tube_assembly_id ', ' quote_date '), Axis = 1) labels = Train.cost.valuestrain = Train.drop ([' Quote_date ' , ' cost ', ' tube_assembly_id '], Axis = 1) # Convert data to NumPy Arraytrain = Np.array (train) test = Np.array (test)From:kaggle Copyright NOTICE: This article for Bo Master original article, without Bo Master permission not reproduced. Ma

"Python" Machinelearning Machine Learning Introduction _ Efficiency Comparison

Efficiency comparison:It's a cliché, but this time with a new module,Run Time Test Module Timeti:1 ImportTimeit2 3normal = Timeit.timeit ('sum (x*x for x in range )', number=10000)4NATIVE_NP = Timeit.timeit ('sum (na*na)',#Repeating part5setup="import numpy as np; na = Np.arange (+)",#Setup runs only once6number=10000)#Number of repetitions7GOOD_NP = Timeit.timeit ('Na.dot (NA)',8setup="import numpy as np; na = Np.arange (+)",9number=10000)Ten One Print('Native Run time:', Normal,'\ n', A

[Machine Learning Python Practice (5)] Sklearn for Integration

90avg/total 0.82 0.78 0.79 329The accuracy of gradient tree boosting is 0.790273556231 Precision recall f1-score support 0 0.92 0.78 0.84 239 1 0.58 0.82 0.68 90avg/total 0.83 0.79 0.80 329Conclusion:Predictive performance: The gradient rise decision tree is larger than the random forest classifier larger than the single decision tree. The industry often uses the stochastic forest c

Data preprocessing of Python machine learning

#数据预处理方法, mainly dealing with the dimension of data and the problem of the same trend.Import NumPy as NPFrom Sklearn Import preprocessing#零均值规范Data=np.random.rand (3,4) #随机生成3行4列的数据Data_standardized=preprocessing.scale (data) #对数据进行归一化处理, that is, each value minus the mean divided by the variance is primarily used for SVM#线性数据变换最大最小化处理Data_scaler=preprocessing. Minmaxscaler (feature_range= (0,1)) #选定区间 (0,1), raw Data-min/(max-min)Data_scaled=data_scaler.fit (data)#数据标准化处理normalizeddata_normaliz

Preparing for machine learning with Python

The language used for machine learning is python. Here's how to get started with Python for "machine learning." (Environment: CentOS 7)1, two important packagesNumPy and SciPy. (http://scipy.org/scipylib/download.html) mainly deal

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