octave machine learning

Omit the use of octave end, later use to see itWeek Three:Logistic Regression:For 0-1 categoriesHypothesis representation:: Sigmoid function or Logistic functionDecision Boundary:Theta's Transpose * small x>=0 is boundaryMay:non-linear decision boundaries, constructing the polynomial of XCost function:Simplified cost function and gradient descent:Because Y has only two values, merging:To find the least biased guide:(The denominator should be ignored)A

IntroductionIn real life, we may unknowingly use a variety of machine learning algorithms every day. For example, when you use Google every time, it works well, and one of the important reasons is that a learning algorithm implemented by Google can "learn" how to rank pages. Every time you use a Facebook or Apple photo-processing app, they can automatically ident

gradient descent algorithm: linear regression Model:　　　　　　　　　　　　　　Linear hypothesis:Squared difference cost function:By substituting each formula, the θ0 and θ1 are respectively biased:By substituting the partial derivative into the gradient descent algorithm, we can realize the process of finding the local optimal solution.The cost function of linear regression is always a convex function, so the gradient descent algorithm only has a minimum value after execution." Batch " gradient descent: use

1. Training error: The error of the learner in the training set, also known as "experience Error"2. Generalization error: The error of the learner on the new sampleObviously, our goal is to get a better learner on a new sample, which is a small generalization error.3. Overfitting: The learner learns the training sample too well, leading to a decline in generalization performance (learning too much ...). Let me think of some people bookworm, reading de

say we have some data points, and now we use a straight line to fit these points, so that this line represents the distribution of data points as much as possible, and this fitting process is called regression.In machine learning tasks, the training of classifiers is the process of finding the best fit curve, so the optimization algorithm will be used next. Before implementing the algorithm, summarize some

Machine learning Notes (i)Today formally began the study of machine learning, in order to motivate themselves to learn, but also to share ideas, decided to send their own experience of learning to the Internet to let everyone share.Bayesian learningLet's start with an exampl

Course Address: Https://class.coursera.org/ntumltwo-002/lectureImportant! Important! Important!1. Shallow-layer neural networks and deep learning2. The significance of deep learning, reduce the burden of each layer of network, simplifying complex features. Very effective for complex raw feature learning tasks, such as machine vision, voice.In the following digita

~ ~): Machine learning, data mining (the second half of the main entry): "Introduction to Data Mining" read a few chapters, feel good. Read the review again. "Machine learning" Stanford Open Class is the main. "Linear Algebra", seventh edition, American Steven J.leon There are examples of applications, looking at

change then the iteration can stop or return to ② to continue the loopExample of using the K-mans algorithm on handwritten digital image dataImportNumPy as NPImportMatplotlib.pyplot as PltImportPandas as PD fromSklearn.clusterImportKmeans#use Panda to read training datasets and test data setsDigits_train = Pd.read_csv ('Https://archive.ics.uci.edu/ml/machine-learning-databases/optdigits/optdigits.tra', hea

software that defeats a number of human participants in an IQ test that requires understanding synonyms, antonyms, and analogies.LeCun ' s group is working on going further. "Language in itself are not so complicated," he says. "What's complicated is have a deep understanding of language and the world that gives you common sense. That's what we ' re really interested in building into machines. " LeCun means common sense as Aristotle used the term:the ability to understand basic physical reality

under-fitting with verification curveValidating a curve is a very useful tool that can be used to improve the performance of a model because he can handle fit and under-fit problems.The verification curve and the learning curve are very similar, but the difference is that the accuracy rate of the model under different parameters is not the same as the accuracy of the different training set size:We get the validation curve for parameter C.Like the Lea

Recently Learning machine learning, saw Andrew Ng's public class, while studying Dr. Hangyuan Li's "Statistical learning method" in this record.On page 12th There is a question about polynomial fitting. Here, the author gives a direct derivative of the request. Here's a detailed derivation.，In this paper, we first look

Time: 2014.06.26 Location: Base Bytes --------------------------------------------------------------------------------------I. Training error and test error The purpose of machine learning or statistical learning is to make the learned model better able to predict not only known data but also unknown data. Different learning