Regression classificationDecision Tree(CART)
Classification Tree
Fitctree
Training classification Binary Decision tree
Regression tree
Fitrtree
Training regression Binary Decision tree
SupportVector machine
Two-class support vector machine
Fitcsvm
Training two classification support vector
1000, then each model will run 1000 times with 999 samples, so the usability is not high in the actual application, and the stability is not good, because it Causes the curve of the 15-6 curve to fluctuate too much and is very unstable. In practical applications, it is seldom to use a cross-validation method.In order to solve the two problems of the cross-validation, a cross-validation method is proposed, in which the sample data set is divided into
In machine learning, often need to calculate the distance between each sample, used for classification, according to distance, different samples grouped into a class; But in the current machine learning algorithm, the distance calculation mode is endless, then this blog is m
At present, the application of machine learning business is more in communication and finance. Large data, machine learning these concepts have been popularized in recent years, but many researchers have worked in this field more than 10 years earlier. Now finally ushered in their own tuyere. I will use the professiona
The essential difference between classification and clustering in machine learning
There are two kinds of big problems in machine learning, one is classification, the other is clustering.In our life, we often do not have too much to distinguish between these two concepts, think clustering is classification, classificat
ProfileThis article is the first of a small experiment in machine learning using the Python programming language. The main contents are as follows:
Read data and clean data
Explore the characteristics of the input data
Analyze how data is presented for learning algorithms
Choosing the right model and
I. BACKGROUND
In machine learning, there are 2 great ideas for supervised learning (supervised learning) and unsupervised learning (unsupervised learning)
Supervised learning, in layman
is all 0. And because it can be deduced that b=1nz∗zt=wt∗ (1NX∗XT) w=wt∗c∗w, this expression actually means that the function of the linear transformation matrix W in the PCA algorithm is to diagonalization the original covariance matrix C. Because diagonalization in linear algebra is obtained by solving eigenvalue and corresponding eigenvector, the process of PCA algorithm can be introduced (the process is mainly excerpted from Zhou Zhihua's "machine
existing learning algorithm". The idea of this kind of method is to adapt the multi-marker training sample to the existing learning algorithm, which is to solve the problem of multi-tagging learning.The representative learning algorithm has a first order method binary relevance, which transforms the multi-tagging
hypothetical function when the input space X and the output to Y are known? Solving this problem is divided into two cases, one is in the reversible case, the solution of the problem is very simple, the right portion of Equation 9-10 is set to 0, such as Equation 9-11.(Equation 9-11)which represents the pseudo-inverse of the Matrix X (pseudo-inverse), note that the input matrix X is in rare cases the Phalanx (n=d+1). The form of this pseudo-inverse matrix and the inverse matrix in the square ha
terminology for minimizing we cost function.
Algorithm:for t = 1 to M:
We get
Using code like this is unroll all the elements and put them into one long vector. Using code like this to get back original matrices.
Gradient Checking:we can approximate the derivative with respect Toθj as follows:
Training:
Week 6:applying
)
Discriminant analysis is mainly in the statistics over there, so I am not very familiar with the temporary find statistics Department of the Boudoir Honey made up a missed lesson. Here we are now learning to sell.
A typical example of discriminant analysis is linear discriminant analysis (Linear discriminant analyses), referred to as LDA.
(notice here not to be confused with the implied Dirichlet distribution (latent Dirichlet allocation), although
For a given set of data and problems, the machine learning method to solve the problem is generally divided into 4 steps:
A Data preprocessing
First, you must ensure that the data is in a format that meets your requirements. The standard data format can be used to fuse algorithms and data sources to facilitate matching operations. In addition, you need to prepare specific data formats for
posteriori, MAP) hypothesis. The method of determining the map assumption is to calculate the posterior probability of each candidate hypothesis with the Bayesian formula. Hmap is the map hypothesis.
HMAP≡ARGMAXH∈HP (h| d) =argmaxh∈hp (D|H) P (h) p (d) =argmaxh∈hp (D|H) p (h)
Here you can see that the P (D) is removed in the last step because it is not a constant dependent on H.
In some cases, we can assume that each assumption in H has the same prior probability, that is, for any hi and HJ, P
1. Decision Tree applicable conditions: The data of different class boundary is non-linear, and by continuously dividing the feature space into a matrix to simulate. There is a certain correlation between features. The number of feature values should be similar, because the information gain is biased towards more numerical characteristics. Advantages: 1. Intuitive decision-making rules; 2. Nonlinear characteristics can be handled; 3. The interaction between variables is considered. Disadvanta
formula shows that if like=c, then the sample may fall within the two interval line, it may also fall on the two interval line above, mainly to see the corresponding relaxation variable value is equal to 0 or greater than 0, the third formula indicates if 0likewTx+b=1 or-1, is the equation, in other places, is an inequality, can not solve B). The representation of the specific visualization is as follows:The KKT condition shows that thelike is not eq
Reprint Please specify source: http://www.cnblogs.com/ymingjingr/p/4271742.htmlDirectory machine Learning Cornerstone Note When you can use machine learning (1) Machine learning Cornerstone Note 2--When you can use
, the above classification idea is the idea of SVM. Can be expressed as: SVM is trying to find a super plane to split the sample, the sample in the positive and inverse examples with the super-plane, but not very perfunctory simple separation, but do the best to make the interval between the positive and inverse of the largest margin. In this way, the results of the classification are more credible, and for
Public Course address:Https://class.coursera.org/ml-003/class/index
INSTRUCTOR:Andrew Ng 1. deciding what to try next (
Determine what to do next
)
I have already introduced some machine learning methods. It is obviously not enough to know the specific process of these methods. The key is to learn how to use them. The so-called best way to master knowledge is to put it into practice. Consider the ear
Twitter-text-Rb-this library can automatically connect and extract user names, lists, and topic tags from Twitter.
General Machine Learning
Ruby machine learning-some machine learning algorithms implemented by ruby.
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