udemy machine learning

In the introduction of recommendation system, we give the general framework of recommendation system. Obviously, the recommendation method is the most core and key part of the whole recommendation system, which determines the performance of the recommended system to a large extent. At present, the main recommended methods include: Based on content recommendation, collaborative filtering recommendation, recommendation based on association rules, based on utility recommendation, based on knowledge

Gradient descent algorithm minimization of cost function J gradient descent Using the whole machine learning minimization first look at the General J () function problem We have J (θ0,θ1) we want to get min J (θ0,θ1) gradient drop for more general functions J (Θ0,θ1,θ2 .....) θn) min J (θ0,θ1,θ2 .....) Θn) How this algorithm works. : Starting from the initial assumption Starting from 0, 0 (or any other valu

similar to LWLR, the formula is described in "machine learning combat". The formula adds a coefficient that we set ourselves, and we take 30 different values to see the change of W.STEP5:Ridge return:#岭回归def ridgeregression (data, L): Xmat = Mat (data) Ymat = Mat (l). T Ymean = mean (Ymat, 0) Ymat = Ymat-ymean Xmean = mean (Xmat, 0) v = var (xmat) Xmat = (Xmat-xmean) /V #取30次不同lam岭回

) for in H: Print(i) for in H.flat: print(i)iterating over a multidimensional array is the first axis :if to perform operations on the elements in each array, we can use the flat property, which is an iterator to the array element :Np.flatten () returns an array that is collapsed into one dimension. However, the function can only be applied to the NumPy object, that is , an array or mat, the normal List of lists is not possible. A = Np.array ([[Up], [3, 4], [5, 6]])print(A.flatten

-centralsonatype-oss-snapshots3.1 Production messagesObjectStreamingproducer {DefMain (args:array[String]) {Val random =NewRandom ()Maximum number of events per secondValMaxevents =6Read the list of possible namesVal Namesresource =This.getClass.getResourceAsStream ("/names.csv")Val names = Scala.io.Source.frominputstream (Namesresource). Getlines (). ToList. Head Split (","). ToseqGenerate a sequence of possible productsVal products =Seq ("IPhone Cover"9.99,"Headphones"5.49,"Samsung Galaxy Cove

of the current node is the middle half of the distance of all its leaf nodes is float (NUMLEAFS)/2.0/plottree.totalw* 1, but since the start Plottree.xoff assignment is not starting from 0, but the left half of the table, so also need to add half the table distance is 1/2/plottree.totalw*1, then add up is (1.0 + float (numleafs))/2.0/ Plottree.totalw*1, so the offset is determined, then the X position becomes Plottree.xoff + (1.0 + float (numleafs))/2.0/PLOTTREE.TOTALW3, for Plottree function p

Original address Mathematics is the foundation of computer technology, linear algebra is the basis of machine learning and deep learning, the best way to understand the knowledge of the data I think is to understand the concept, mathematics is not only used for exams in school, but also the essential basic knowledge of the work, in fact, there are many interestin

http://blog.csdn.net/zhangyingchengqi/article/details/50969064First, machine learning1. Includes nearly 400 datasets of different sizes and types for classification, regression, clustering, and referral system tasks. The data set list is located at:http://archive.ics.uci.edu/ml/2. Kaggle datasets, Kagle data sets for various competitionsHttps://www.kaggle.com/competitions3.Second, computer vision"Machine

a good effect, basically do not know what method of time can first try random forest.SVM (Support vector machine) The core idea of SVM is to find the interface between different categories, so that the two types of samples as far as possible on both sides of the surface, and the separation of the interface as much as possible. The earliest SVM was planar and limited in size. But using the kernel function (kernel functions), we can make the plane proj

http://sourceforge.net/projects/numpy/files/download the corresponding version of the NumPy, everywhere, find a not python2.7Use Pip, please.Pip Install NumPyDownload finished, the hint does not install C + +, meaning is also to install VS2008, but installed is VS2012, had to download a VC for Pythonhttp://www.microsoft.com/en-us/download/confirmation.aspx?id=44266Re-pip, wait for the most of the day, the final count is successfulInput command introduced NumPyFrom numpy Import *Operation:InputRa

1. Common steps 2. Chinese participle 1 This is relative to the English text affective analysis, Chinese unique preprocessing. 2 Common methods: Based on the dictionary, rule-based, Statistical, based on the word annotation, based on artificial intelligence. 3 Common tools: Hit-language cloud, Northeastern University Niutrans statistical Machine translation system, the Chinese Academy of Sciences Zhang Huaping Dr. Ictclas, Posen technology, stutterin

This is already the third algorithm of machine learning. Speaking of the simple Bayes, perhaps everyone is not very clear what. But if you have studied probability theory and mathematical statistics, you may have some idea of Bayesian theorem, but you can't remember where it is. Yes, so important a theorem, in probability theory and mathematical statistics, only a very small space to introduce it. This is n

Definition of successive descent method: For a given set of equations, use the formula:where k is the number of iterations (k=0,1,2,... ）The method of finding approximate solution by stepwise generation is called iterative method If it exists (recorded as), it is said that this iterative method converges, obviously is the solution of the equations, otherwise called this iterative method divergence. Study the convergence of {}. Introducing Error Vectors:Get:Recursion gets:To inve

Experimental purposes Recently intend to systematically start learning machine learning, bought a few books, but also find a lot of practicing things, this series is a record of their learning process, from the most basic KNN algorithm began; experiment Introduction Language: Python GitHub Address: LUUUYI/KNNExperiment

1. Vector Norm Norm, Norm, is a concept similar to "Length" in mathematics, which is actually a kind of function.The regularization (regularization) and sparse coding (Sparse coding) in machine learning are very interesting applications.For Vector a∈rn A\in r^n, its LP norm is | | a| | p= (∑IN|AI|P) 1p (1) | | a| | _p= (\sum_i^n |a_i|^p) ^{\frac 1 p} \tag 1Commonly used are: L0 NormThe number of elements i

Cross entropy cost function 1. Cross-entropy theory Cross entropy is relative to entropy, as covariance and variance. Entropy examines the expectation of a single information (distribution): H (p) =−∑I=1NP (xi) Logp (xi) Cross-Entropy examines the expectations of two of information (distributions):H (P,Q) =−∑I=1NP (xi) logq (xi)For details, please see Wiki Cross entropy y = Tf.placeholder (Dtype=tf.float32, Shape=[none, ten]) ... Scores = Tf.matmul (H, W) + b probs = Tf.nn.softmax (scores) l

Vi. more hyper-parameters in grid search and K-nearest algorithmVii. Normalization of data Feature ScalingSolution: Map all data to the same scaleViii. the Scaler in Scikit-learnpreprocessing.pyImportNumPy as NPclassStandardscaler:def __init__(self): Self.mean_=None Self.scale_=NonedefFit (self, X):"""get the mean and variance of the data based on the training data set X""" assertX.ndim = = 2,"The dimension of X must be 2"Self.mean_= Np.array ([Np.mean (X[:,i]) forIinchRange (x.shape[1]))

1. The complete course of statistics all of statistics Carnegie Kimelon Wosseman 2. Fourth edition, "Probability Theory and Mathematical Statistics" Morris. Heidegger, Morris H.degroot, and Mark. Schevish (Mark j.shervish) 3. Introduction to Linear algebra, Gilbert. Strong--Online video tutorials are classic 4. "Numerical linear algebra", Tracy Füssen. Lloyd and David. Bao Textbooks suitable for undergraduates 5. Predictive data analysis of machine