American Group Shop Evaluation Language Processing and classification (NLP)
The First Data Analysis section
The second visualization section,
This article is the third of the series, text classification
The main use of the package has Jieba,sklearn,pandas, this post mainly uses the word bag model (bag of words), the text in the form of a numerical feature vector (each document constructs a eigenvector, there are a lot of 0, the value ap
I. What is characteristic engineering?There is a saying that is widely circulated in the industry: data and features determine the upper limit of machine learning, and models and algorithms only approximate this limit. What is the characteristic project in the end? As the name implies, its essence is an engineering activity designed to maximize the extraction of features from raw data for use by algorithms and models. By summarizing and concluding, it is believed that feature engineering include
Article:http://python.jobbole.com/81215/Python's library of functions is so powerful! After reading this blog will never use MATLAB ~ ~This article uses "panda" to read the CSV data, use the Linear_model in "Sklearn" to train the model and make a linear prediction using the "matplotlib" The fitting situation is represented by a graph.The table below is the table used to train the model:The code is as follows:#-*-coding:utf-8-*-" "Created on 2016/11/26
LinearRegressionFits a linear model with coefficients to minimize the residual sum of squares between the observed responses in the Datas ET, and the responses predicted by the linear approximation. Mathematically it solves a problem of the form:Minimization of principle: from sklearn Import Linear_model>>> CLF = Linear_model. Linearregression ()>>> clf.fit ([[00], [11], [22 ]], [012]) linearregression (copy_x=true, Fit_intercept=true, N_jobs =1, nor
principleData Normalization (normalization) is a vector that transforms each sample (vector) of data into a unit norm, each of which is independent of each other. In effect, each component value in the vector is divided by the normalization factor. Common regularization factors are L1, L2, and Max. Suppose, for a vector of length n, the formula of its regularization factor Z, as follows:Note: Max is different from infinity norm in that the infinity norm needs to take the absolute value of all th
Want to learn about TensorFlow, import online source, found Sklearn has been introduced failure.Use directly under the commandPip Install-u numpyPip Install-u scipyPip Install-u Scikit-learnThe Scikit extension can also be found with the PIP list, which can be introduced directly into the Python command as well as import Sklearn, but the extension cannot be introduced normally in the project.
The introduct
My Computer small white one, recently learned Python, in trying to learn the text classification model encountered a problem, on the Pycharm import sklearn problem.
I consolidated anaconda this package on the pycharm2017.3 and installed anaconda2 and Anaconda3, anaconda2 as the default interpreter, and the corresponding version is python2.7. When importing the Sklearn library on Pycharm, the following prob
When using the Sklearn Roc_curve () function, it is found that the returned results are not the same as imagined, theoretically threshold should take all y_score (i.e. model predictive values). But the results of roc_curve () only output part of the threhold. From the source found the reason.
Initial data:
Y_true = [0, 0, 1, 0, 0, 1, 0, 1, 0, 0]
y_score = [0.31689620142873609, 0.32367439192936548, 0.42600526758001989, 0.38 769987193780364, 0.366754101
The K-fold verification proposed in this paper is the Stratifiedkfold method in the Sklearn package in Python.The idea of the method is described: http://scikit-learn.org/stable/modules/cross_validation.htmlStratifiedkfold Is a variation of K-fold which returns stratified Folds:each set contains approximately the same percentage of samples of each target class as the complete set.TranslationStratifiedkfold is the one that sets each sample in the data
Preface : Recent bioinformatics has talked about the AUC,Roc , two indicators, is doing project, requires the ROC curve,Sklearn inside has corresponding functions, so learn to learn. Auc:ROC:Specific use of reference Sklearn:Http://scikit-learn.org/stable/modules/generated/sklearn.metrics.roc_curve.htmlhttp://scikit-learn.org/stable/auto_examples/model_selection/plot_roc_crossval.html# Example-model-selection-plot-roc-crossval-pyhttp://www.tuicool.com
"" "Function: Logical regression Description: Author: Tang Tianze Blog: http://blog.csdn.net/u010837794/article/details/Date: 2017-08-14" "," "Import the package required for the project" "" Imports Nump Y as NP import matplotlib.pyplot as PLT # using Cross-validation method, the dataset is divided into training set test set from sklearn.model_selection import Train_test_split F Rom sklearn import datasets from Sklearn.linear_model import logisticre
the Sklean in Python already integrates the SVM algorithm, It includes fit (), predict (), etc., so we can get the results of the classification by simply inputting the training samples and markers, as well as the model parameters. There are many implementations of this code, and the SVC parameters are described in:Detailed Address: Http://scikit-learn.org/stable/modules/generated/sklearn.svm.SVC.html#sklearn.svm.SVCBut for the implementation of LIBSVM in the degree of membership calculation has
' virginica ']To draw a histogram with a feature:X_index = 3colors = [' Blue ', ' red ', ' green ']for label, color in Zip (range (len (iris.target_names)), colors): plt.hist ( Iris.data[iris.target==label, X_index], label = Iris.target_names[label], color=color) Plt.xlabel (iris.feature_ Names[x_index]) plt.legend (loc= ' upper right ') plt.show ()Plot a scatter plot with two features:X_index = 0y_index = 1colors = [' Blue ', ' red ', ' green ']for label, color in Zip (range (le
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
factors other than the data set.2) orthogonal between the main components, can eliminate the interaction between the original data components of the factors.3) Calculation method is simple, the main operation is eigenvalue decomposition, easy to achieve.The main drawbacks of PCA algorithms are:1) The meaning of each characteristic dimension of principal component has certain fuzziness, which is not better than the interpretation of original sample characteristics.2) The non-principal component
When we classify, we need to divide the data into two parts, part of which is the test data, part of the training data. Sklearn can randomly select the training data and test data according to the set proportion, and the sample and label are the corresponding groupings.The experimental code is as follows:
#!/usr/bin/env python
#-*-coding:utf-8-*-"" "
Feature: Datasets are scaled to training sets and test set
times: March 11, 2017 12:48:57
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