This chapter will be divided into two sections:
The Set/get of KVC
KVC Key-value path
The Set/get of KVCThere are 3 variables in Class A, all private permissions, and for access rights, see the OBJECTIVE-C member Variable "A.h@interface a:nsobject{@private *str; Nsinteger value; //Note there are no asterisks here oh oh *array;} @enda.m.: Override the description function for NSLog@implementation A /* * * */-(NSString *) description{return [nsstring stringWithFor
I. bootstrps bagging boosting
These concepts are frequently used. Now I have carefully studied them: They all belong to the integrated learning method. , (For example, bagging, boosting, stacking), which integrates the training learner, and the principle is derived from the PAC learning model (probably approximately correctk ). Kearns and valiant indicate that in the PAC learning model, if onePolynomial-le
Document directory
Boosting features
Indexing date
Indexing number
Sort
Indexwriter adjustment of Lucene
Ramdirectory and fsdirectory Conversion
Optimize indexes for queries)
Concurrent operations Lucene and locking mechanisms
Locing
Debug indexwriter
Boosting features
Luncene provides a configurable boosting parameter for document and field. The purp
1.What isTreelink
Treelink is the internal name of Alibaba Group. Its Academic name is gbdt (gradient boosting demo-tree, gradient escalation Decision Tree ). Gbdt is related to "model combination + decision tree"AlgorithmThe other is the random forest (random forest), which is simpler than gbdt.
1.1Decision tree
One of the most widely used classification algorithms, the result of model learning is a decision tree, which can be expressed as mult
http://geek.csdn.net/news/detail/201207
Xgboost:extreme Gradient BoostingProject Address: Https://github.com/dmlc/xgboost
Tianqi Chen http://homes.cs.washington.edu/~tqchen/was originally developed to implement an extensible, portable, distributed gradient boosting (GBDT, GBRT or GBM) algorithm for a library that can be Installed and applied to C++,python,r,julia,java,scala,hadoop, many co-authors are now developing maintenance.
The algorithm applied
In general, we can improve the accuracy of a predictive model in two ways: Refine feature engineering (feature engineering) or directly use the boosting algorithm. Through the trials of a large number of data science contests, we can find that people prefer the boosting algorithm because it tends to save time when it produces similar results compared to other methods.There are many kinds of
Recently due to friends invited to help an open-source game "plug" to do a i18n solution, just as WPF did, before the relevant experience, on the busy one weeks finally settled, has been submitted to the author, now here to do a share.Here, share my personal fork. GitHub Address: Https://github.com/Cuiyansong/Hearthstone-Deck-TrackerWhat is i18nIn simple terms, it is multi-lingual, why multilingual is called i18n, please refer to the epilogue.How to A
whose scores are greater than 0.
Docfreq_t: Total number of documents containing item t
Idf_t: log (numdocs/docfreq + 1) + 1.0
Norm_q: SQRT (sum_t (tf_q * idf_t) ^ 2 ))
Norm_d_t: In document D, the square root of the total number of all items in the same domain as item t
Boost_t: increase factor of item T, generally 1.0
Coord_q_d: In document D, the number of hit items divided by the total number of items in the query Q
3.3. Other Lucene features3.3.1. Boos
Use sklearn for integration learning-practice, sklearn IntegrationSeries
Using sklearn for Integrated Learning-Theory
Using sklearn for Integrated Learning-Practice
Directory
1. Details about the parameters of Random Forest and Gradient Tree Boosting2. How to adjust parameters?2.1 adjustment objective: coordination of deviation and variance2.2 Impact of parameters on overall model performance2.3 A simple solution: greedy coordinate Descent Method2.3.1 Random Forest parameter adjustment case:
Reprint Address: http://blog.csdn.net/w28971023/article/details/8240756 GBDT (Gradient boosting decision tree), also known as MART (multiple Additive Regression tree), is an iterative decision tree algorithm, which consists of multiple decision trees, The conclusions of all the trees are summed up to make the final answer. It is considered to be a strong generalization capability (generalization) algorithm with SVM at the beginning of the proposed met
Label: style blog HTTP Io color OS ar sp
From: http://blog.csdn.net/weixingstudio/article/details/7631241
Haar features and integral Diagram 1. Introduction of AdaBoost method 1.1 proposal and Development of boosting method
Before learning about the AdaBoost method, let's take a look at the boosting method.
To answer a question of "yes" or "no", a 50% accuracy rate can be obtained by random guesses.
.
SVM theory is perfect and widely used. Likewise, logistic regression is widely used, similar to SVM.
When the data is big sample data, the linear SVM model is better.
Lesson 1 nonlinear SVM
Rkhs representation theorem: The model parameter is a linear combination of training samples in the linear subspaces of training samples. This applies not only to SVM, but also to other models, such as perception machines, RBF Networks, LVQ, boosting, and logi
Introduction to Elasticlunr. js and introduction to elasticlunr. jsElasticlunr. js
Elasticlurn. js is a lightweight full-text search engine in Javascript for browser search and offline search.Elasticlunr. js is developed based on Lunr. js, but more flexible than lunr. js. Elasticlunr. js provides Query-Time boosting and field search.Elasticlunr. js is a bit like Solr, but much smaller and not as bright, but also provide flexible configuration and que
, and the load is light, so the throughput of users in the small station is high. Therefore, the user experience of the macro site is obviously different from that of the small site.
Key Technology for future wireless network evolution-MSA
With the continuous development of wireless networks, MSA uses multi-standard, multi-carrier, and multi-layer networks for in-depth integration, it can effectively solve the problems of mobility support to be improved, prominent interference problems, and low
effective model is based on the classification or regression tree tree model. Here are some of the information that has been made simple:Basics: Classification and regression treeDecision trees should be very familiar with, in fact, the space with a super-plane division of a method, each time the division (select split node) will be the current space in one, each leaf node is in the space of a disjoint area. The sample can be divided into a leaf node to obtain the classification result accordin
When I recently made a mobile-phone page, I encountered a strange problem: The font display size is inconsistent with the size specified in the CSS. You can view this demo (remember to open chrome DevTools).As shown, you can find that the originally specified font size is 24px, but the final calculation is 53px, see this bizarre result, my heart cursed a sentence: What a ghost!Then began to troubleshoot the problem: A label caused? One of the CSS causes? Or a certain sentence JS code caused by.
This paper mainly introduces the principle of adaptive lifting Learning algorithm (Adaptive boosting,adaboost), because it involves classifiers, and classifiers are often based on some sample features, so this paper introduces the most commonly used Adaboost algorithm combined with haar-like characteristics. The algorithm is widely used in human face detection, and then it is applied in other related target detection.1.Adaboost AlgorithmPrevious exist
Elasticlunr.jsElasticlurn.js is a lightweight full-text search engine in Javascript for browser search and offline search.Elasticlunr.js is developed based on Lunr.js, but more flexible than lunr.js. Elasticlunr.js provides query-time boosting and field search.Elasticlunr.js is a bit like SOLR, but much smaller and not as bright, but also provide flexible configuration and query-t IME boosting.Key Features comparing with Lunr.js
Query-time
GBDT is all called Gradient boosting decision Tree. as the name implies, it is a categorical regression algorithm based on the decision tree (decision) implementation. It is not difficult to find that GBDT has two parts: gradient boosting, decision tree. boosting as a model combination, and gradient descent have a deep source, what is the relationship between t
the classification performance of random forests. Because of their introduction, random forests are not prone to overfitting and have good noise immunity (e.g., insensitive to default values). A detailed description of the random forest can be found in the previous post, Random Forest (Forest).5. GBDTThe iterative decision Tree GBDT (Gradient boosting decision tree) is also known as Mart (multiple Additive Regression tree) or GBRT (Gradient
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