Misplaced Pages

#350649

86-470: Because total cholesterol and hospital length of stay are typically not uniform factors across different hospitals and may vary in different countries, an additional model that included only seven of the nine variables was evaluated. This yielded a performance close to the one of using all nine variables and resulted in the following associations with increased mortality: INR, creatinine, total bilirubin, sodium, WBC, albumin, and age. The development of MELD-Plus

172-400: A search algorithm to search through the space of possible features and evaluate each subset by running a model on the subset. Wrappers can be computationally expensive and have a risk of over fitting to the model. Filters are similar to wrappers in the search approach, but instead of evaluating against a model, a simpler filter is evaluated. Embedded techniques are embedded in, and specific to,

258-509: A static web hosting service for blogs , project documentation, and books. All GitHub Pages content is stored in a Git repository as files served to visitors verbatim or in Markdown format. GitHub is integrated with Jekyll static website and blog generator and GitHub continuous integration pipelines. Each time the content source is updated, Jekyll regenerates the website and automatically serves it via GitHub Pages infrastructure. Like

344-409: A Campus Expert, applicants must complete an online training course with multiple modules to develop community leadership skills. GitHub also provides some software as a service (SaaS) integrations for adding extra features to projects. Those services include: GitHub Sponsors allows users to make monthly money donations to projects hosted on GitHub. The public beta was announced on May 23, 2019, and

430-520: A candidate feature (or set of features) and the desired output category. There are, however, true metrics that are a simple function of the mutual information; see here . Other available filter metrics include: The choice of optimality criteria is difficult as there are multiple objectives in a feature selection task. Many common criteria incorporate a measure of accuracy, penalised by the number of features selected. Examples include Akaike information criterion (AIC) and Mallows's C p , which have

516-406: A cloud provider and has been available as of November 2011 . In November 2020, source code for GitHub Enterprise Server was leaked online in an apparent protest against DMCA takedown of youtube-dl . According to GitHub, the source code came from GitHub accidentally sharing the code with Enterprise customers themselves, not from an attack on GitHub servers. In 2008, GitHub introduced GitHub Pages,

602-559: A community, platform and business. Under Microsoft, the service was led by Xamarin 's Nat Friedman , reporting to Scott Guthrie , executive vice president of Microsoft Cloud and AI. Nat Friedman resigned November 3, 2021; he was replaced by Thomas Dohmke. There have been concerns from developers Kyle Simpson, JavaScript trainer and author, and Rafael Laguna, CEO at Open-Xchange over Microsoft's purchase, citing uneasiness over Microsoft's handling of previous acquisitions, such as Nokia's mobile business and Skype . This acquisition

688-649: A global quadratic programming optimization problem as follows: where F n × 1 = [ I ( f 1 ; c ) , … , I ( f n ; c ) ] T {\displaystyle F_{n\times 1}=[I(f_{1};c),\ldots ,I(f_{n};c)]^{T}} is the vector of feature relevancy assuming there are n features in total, H n × n = [ I ( f i ; f j ) ] i , j = 1 … n {\displaystyle H_{n\times n}=[I(f_{i};f_{j})]_{i,j=1\ldots n}}

774-439: A global optimum. There are many metaheuristics, from a simple local search to a complex global search algorithm. The feature selection methods are typically presented in three classes based on how they combine the selection algorithm and the model building. Filter type methods select variables regardless of the model. They are based only on general features like the correlation with the variable to predict. Filter methods suppress

860-555: A later time. In addition, GitHub supports the following formats and features: GitHub's Terms of Service do not require public software projects hosted on GitHub to meet the Open Source Definition . The terms of service state, "By setting your repositories to be viewed publicly, you agree to allow others to view and fork your repositories." GitHub Enterprise is a self-managed version of GitHub with similar functionality. It can be run on an organization's hardware or

946-414: A model. Many popular search approaches use greedy hill climbing , which iteratively evaluates a candidate subset of features, then modifies the subset and evaluates if the new subset is an improvement over the old. Evaluation of the subsets requires a scoring metric that grades a subset of features. Exhaustive search is generally impractical, so at some implementor (or operator) defined stopping point,

SECTION 10

#1732782436351

1032-676: A penalty of 2 for each added feature. AIC is based on information theory , and is effectively derived via the maximum entropy principle . Other criteria are Bayesian information criterion (BIC), which uses a penalty of log ⁡ n {\displaystyle {\sqrt {\log {n}}}} for each added feature, minimum description length (MDL) which asymptotically uses log ⁡ n {\displaystyle {\sqrt {\log {n}}}} , Bonferroni / RIC which use 2 log ⁡ p {\displaystyle {\sqrt {2\log {p}}}} , maximum dependency feature selection, and

1118-577: A registered user account, users can have discussions, manage repositories, submit contributions to others' repositories, and review changes to code . GitHub began offering limited private repositories at no cost in January 2019 (limited to three contributors per project). Previously, only public repositories were free. On April 14, 2020, GitHub made "all of the core GitHub features" free for everyone, including "private repositories with unlimited collaborators." The fundamental software that underpins GitHub

1204-416: A search engine are available for issue tracking. For version control, Git (and, by extension, GitHub) allows pull requests to propose changes to the source code. Users who can review the proposed changes can see a diff between the requested changes and approve them. In Git terminology, this action is called "committing" and one instance of it is a "commit." A history of all commits is kept and can be viewed at

1290-510: A significant user of GitHub, using it to host open-source projects and development tools such as .NET Core , Chakra Core , MSBuild , PowerShell , PowerToys , Visual Studio Code , Windows Calculator , Windows Terminal and the bulk of its product documentation (now to be found on Microsoft Docs ). On June 4, 2018, Microsoft announced its intent to acquire GitHub for US$ 7.5 billion (~$ 8.96 billion in 2023). The deal closed on October 26, 2018. GitHub continued to operate independently as

1376-401: A statement denying Horvath's allegations. However, following an internal investigation, GitHub confirmed the claims. GitHub's CEO Chris Wanstrath wrote on the company blog, "The investigation found Tom Preston-Werner in his capacity as GitHub's CEO acted inappropriately, including confrontational conduct, disregard of workplace complaints, insensitivity to the impact of his spouse's presence in

1462-496: A subsidiary of Microsoft since 2018. It is commonly used to host open source software development projects. As of January 2023 , GitHub reported having over 100 million developers and more than 420 million repositories , including at least 28 million public repositories. It is the world's largest source code host as of June 2023 . Over five billion developer contributions were made to more than 500 million open source projects in 2024. The development of

1548-403: A total of 135,000 repositories. In 2010, GitHub was hosting 1 million repositories. A year later, this number doubled. ReadWriteWeb reported that GitHub had surpassed SourceForge and Google Code in total number of commits for the period of January to May 2011. On January 16, 2013, GitHub passed the 3 million users mark and was then hosting more than 5 million repositories. By the end of

1634-504: A variable similar to the variables selected at previous tree nodes for splitting the current node. Regularized trees only need build one tree model (or one tree ensemble model) and thus are computationally efficient. Regularized trees naturally handle numerical and categorical features, interactions and nonlinearities. They are invariant to attribute scales (units) and insensitive to outliers , and thus, require little data preprocessing such as normalization . Regularized random forest (RRF)

1720-455: A variety of new criteria that are motivated by false discovery rate (FDR), which use something close to 2 log ⁡ p q {\displaystyle {\sqrt {2\log {\frac {p}{q}}}}} . A maximum entropy rate criterion may also be used to select the most relevant subset of features. Filter feature selection is a specific case of a more general paradigm called structure learning . Feature selection finds

1806-491: A website that enables designers to market royalty-free digital images . The illustration GitHub chose was a character that Oxley had named Octopuss. Since GitHub wanted Octopuss for their logo (a use that the iStock license disallows), they negotiated with Oxley to buy exclusive rights to the image. GitHub renamed Octopuss to Octocat, and trademarked the character along with the new name. Later, GitHub hired illustrator Cameron McEfee to adapt Octocat for different purposes on

SECTION 20

#1732782436351

1892-501: A “trough of disillusionment” by fostering a stronger appreciation of the technology's capabilities and limitations." However, the authors further added "Although predictive algorithms cannot eliminate medical uncertainty, they already improve allocation of scarce health care resources, helping to avert hospitalization for patients with low-risk pulmonary embolisms (PESI) and fairly prioritizing patients for liver transplantation by means of MELD scores." A sample code for calculating MELD-Plus

1978-469: Is Git itself, written by Linus Torvalds , creator of Linux. The additional software that provides the GitHub user interface was written using Ruby on Rails and Erlang by GitHub, Inc. developers Wanstrath, Hyett, and Preston-Werner. The primary purpose of GitHub is to facilitate the version control and issue tracking aspects of software development. Labels, milestones, responsibility assignment, and

2064-1644: Is a kernel-based independence measure called the (empirical) Hilbert-Schmidt independence criterion (HSIC), tr ( ⋅ ) {\displaystyle {\mbox{tr}}(\cdot )} denotes the trace , λ {\displaystyle \lambda } is the regularization parameter, K ¯ ( k ) = Γ K ( k ) Γ {\displaystyle {\bar {\mathbf {K} }}^{(k)}=\mathbf {\Gamma } \mathbf {K} ^{(k)}\mathbf {\Gamma } } and L ¯ = Γ L Γ {\displaystyle {\bar {\mathbf {L} }}=\mathbf {\Gamma } \mathbf {L} \mathbf {\Gamma } } are input and output centered Gram matrices , K i , j ( k ) = K ( u k , i , u k , j ) {\displaystyle K_{i,j}^{(k)}=K(u_{k,i},u_{k,j})} and L i , j = L ( c i , c j ) {\displaystyle L_{i,j}=L(c_{i},c_{j})} are Gram matrices, K ( u , u ′ ) {\displaystyle K(u,u')} and L ( c , c ′ ) {\displaystyle L(c,c')} are kernel functions, Γ = I m − 1 m 1 m 1 m T {\displaystyle \mathbf {\Gamma } =\mathbf {I} _{m}-{\frac {1}{m}}\mathbf {1} _{m}\mathbf {1} _{m}^{T}}

2150-450: Is an approximation of the theoretically optimal maximum-dependency feature selection algorithm that maximizes the mutual information between the joint distribution of the selected features and the classification variable. As mRMR approximates the combinatorial estimation problem with a series of much smaller problems, each of which only involves two variables, it thus uses pairwise joint probabilities which are more robust. In certain situations

2236-621: Is available in GitHub . Feature selection In machine learning, feature selection is the process of selecting a subset of relevant features (variables, predictors) for use in model construction. Feature selection techniques are used for several reasons: The central premise when using feature selection is that data sometimes contains features that are redundant or irrelevant , and can thus be removed without incurring much loss of information. Redundancy and irrelevance are two distinct notions, since one relevant feature may be redundant in

2322-521: Is available. Calculators capable of calculating MELD and MELD-Na are available. Johnson HR. Developing a new score: how machine learning improves risk prediction. Livernois C. Harvard researchers develop predictive model for cirrhosis outcomes. Goedert J. IBM taps machine learning to predict cirrhosis mortality rates. Cohen JK. Harvard, IBM researchers develop prediction model for cirrhosis outcomes. Massachusetts General Hospital (Snapshot of Science). A call for an additional validation of MELD-Plus

2408-479: Is deciding when to stop the algorithm. In machine learning, this is typically done by cross-validation . In statistics, some criteria are optimized. This leads to the inherent problem of nesting. More robust methods have been explored, such as branch and bound and piecewise linear network. Subset selection evaluates a subset of features as a group for suitability. Subset selection algorithms can be broken up into wrappers, filters, and embedded methods. Wrappers use

2494-531: Is defined as follows: The r c f i {\displaystyle r_{cf_{i}}} and r f i f j {\displaystyle r_{f_{i}f_{j}}} variables are referred to as correlations, but are not necessarily Pearson's correlation coefficient or Spearman's ρ . Hall's dissertation uses neither of these, but uses three different measures of relatedness, minimum description length (MDL), symmetrical uncertainty , and relief . Let x i be

2580-490: Is formulated as follows: The score uses the conditional mutual information and the mutual information to estimate the redundancy between the already selected features ( f j ∈ S {\displaystyle f_{j}\in S} ) and the feature under investigation ( f i {\displaystyle f_{i}} ). For high-dimensional and small sample data (e.g., dimensionality > 10 and

2666-510: Is indicated on the gist page. GitHub launched a new program called the GitHub Student Developer Pack to give students free access to more than a dozen popular development tools and services. GitHub partnered with Bitnami , Crowdflower , DigitalOcean , DNSimple, HackHands , Namecheap , Orchestrate, Screenhero, SendGrid , Stripe , Travis CI , and Unreal Engine to launch the program. In 2016, GitHub announced

MELD-Plus - Misplaced Pages Continue

2752-401: Is one type of regularized trees. The guided RRF is an enhanced RRF which is guided by the importance scores from an ordinary random forest. A metaheuristic is a general description of an algorithm dedicated to solve difficult (typically NP-hard problem) optimization problems for which there is no classical solving methods. Generally, a metaheuristic is a stochastic algorithm tending to reach

2838-544: Is projected to save 50–60 lives total per year. Furthermore, a study published in the New England Journal of Medicine in 2008, estimated that using MELD-Na instead of MELD would save 90 lives for the period from 2005 to 2006. In his viewpoint published in June 2018, co-creator of MELD-Plus, Uri Kartoun, suggested that "...MELD-Plus, if incorporated into hospital systems, could save hundreds of patients every year in

2924-424: Is required by law. This includes keeping public repositories services, including those for open source projects, available and accessible to support personal communications involving developers in sanctioned regions. Developers who feel that they should not have restrictions can appeal for the removal of said restrictions, including those who only travel to, and do not reside in, those countries. GitHub has forbidden

3010-437: Is that it can be solved simply via finding the dominant eigenvector of Q , thus is very scalable. SPEC CMI also handles second-order feature interaction. In a study of different scores Brown et al. recommended the joint mutual information as a good score for feature selection. The score tries to find the feature, that adds the most new information to the already selected features, in order to avoid redundancy. The score

3096-476: Is the ℓ 1 {\displaystyle \ell _{1}} -norm. HSIC always takes a non-negative value, and is zero if and only if two random variables are statistically independent when a universal reproducing kernel such as the Gaussian kernel is used. The HSIC Lasso can be written as where ‖ ⋅ ‖ F {\displaystyle \|\cdot \|_{F}}

3182-516: Is the Frobenius norm . The optimization problem is a Lasso problem, and thus it can be efficiently solved with a state-of-the-art Lasso solver such as the dual augmented Lagrangian method . The correlation feature selection (CFS) measure evaluates subsets of features on the basis of the following hypothesis: "Good feature subsets contain features highly correlated with the classification, yet uncorrelated to each other". The following equation gives

3268-481: Is the Markov blanket of the target node, and in a Bayesian Network, there is a unique Markov Blanket for each node. There are different Feature Selection mechanisms around that utilize mutual information for scoring the different features. They usually use all the same algorithm: The simplest approach uses the mutual information as the "derived" score. However, there are different approaches, that try to reduce

3354-399: Is the centering matrix, I m {\displaystyle \mathbf {I} _{m}} is the m -dimensional identity matrix ( m : the number of samples), 1 m {\displaystyle \mathbf {1} _{m}} is the m -dimensional vector with all ones, and ‖ ⋅ ‖ 1 {\displaystyle \|\cdot \|_{1}}

3440-483: Is the matrix of feature pairwise redundancy, and x n × 1 {\displaystyle \mathbf {x} _{n\times 1}} represents relative feature weights. QPFS is solved via quadratic programming. It is recently shown that QFPS is biased towards features with smaller entropy, due to its placement of the feature self redundancy term I ( f i ; f i ) {\displaystyle I(f_{i};f_{i})} on

3526-505: Is usually used for larger projects. Tom Preston-Werner débuted the feature at a Ruby conference in 2008. Gist builds on the traditional simple concept of a pastebin by adding version control for code snippets, easy forking, and TLS encryption for private pastes. Because each "gist" is its own Git repository, multiple code snippets can be contained in a single page, and they can be pushed and pulled using Git. Unregistered users could upload Gists until March 19, 2018, when uploading Gists

MELD-Plus - Misplaced Pages Continue

3612-570: The Svalbard Global Seed Vault . The archive contained the code of all active public repositories, as well as that of dormant but significant public repositories. The 21 TB of data was stored on piqlFilm archival film reels as matrix (2D) barcode ( Boxing barcode ), and is expected to last 500–1,000 years. The GitHub Archive Program is also working with partners on Project Silica, in an attempt to store all public repositories for 10,000 years. It aims to write archives into

3698-808: The FRMT algorithm. This is a survey of the application of feature selection metaheuristics lately used in the literature. This survey was realized by J. Hammon in her 2013 thesis. Some learning algorithms perform feature selection as part of their overall operation. These include: GitHub GitHub ( / ˈ ɡ ɪ t h ʌ b / ) is a developer platform that allows developers to create, store, manage and share their code. It uses Git software, which provides distributed version control of access control , bug tracking , software feature requests, task management , continuous integration , and wikis for every project. Headquartered in California , it has been

3784-587: The Fast Correlation Based Filter (FCBF) algorithm. Wrapper methods evaluate subsets of variables which allows, unlike filter approaches, to detect the possible interactions amongst variables. The two main disadvantages of these methods are: Embedded methods have been recently proposed that try to combine the advantages of both previous methods. A learning algorithm takes advantage of its own variable selection process and performs feature selection and classification simultaneously, such as

3870-541: The GitHub platform began on October 19, 2007. The site was launched in April 2008 by Tom Preston-Werner , Chris Wanstrath , P. J. Hyett and Scott Chacon after it had been available for a few months as a beta release . Its name was chosen as a compound of Git and hub . GitHub, Inc. was originally a flat organization with no middle managers, instead relying on self-management . Employees could choose to work on projects that interested them ( open allocation ), but

3956-732: The United States alone." A review specifying alternatives to MELD, including MELD-Na, MELD-sarcopenia, UKELD, D-MELD, iMELD, and MELD-Plus, was published in June 2019 in Seminars in Liver Disease. The optimized prediction of mortality (OPOM) score is another tool that has been proposed to serve as an alternative to Model for End-Stage Liver Disease . A review published in Transplantation in February 2020 highlighted

4042-427: The algorithm may underestimate the usefulness of features as it has no way to measure interactions between features which can increase relevancy. This can lead to poor performance when the features are individually useless, but are useful when combined (a pathological case is found when the class is a parity function of the features). Overall the algorithm is more efficient (in terms of the amount of data required) than

4128-439: The algorithm, and it is these evaluation metrics which distinguish between the three main categories of feature selection algorithms: wrappers, filters and embedded methods. In traditional regression analysis , the most popular form of feature selection is stepwise regression , which is a wrapper technique. It is a greedy algorithm that adds the best feature (or deletes the worst feature) at each round. The main control issue

4214-463: The chief executive set salaries. In 2014, the company added a layer of middle management in response to serious harassment allegations against its senior leadership. As a result of the scandal, Tom Preston-Werner resigned from his position as CEO. GitHub was a bootstrapped start-up business , which in its first years provided enough revenue to be funded solely by its three founders and start taking on employees. In July 2012, four years after

4300-435: The combination of a search technique for proposing new feature subsets, along with an evaluation measure which scores the different feature subsets. The simplest algorithm is to test each possible subset of features finding the one which minimizes the error rate. This is an exhaustive search of the space, and is computationally intractable for all but the smallest of feature sets. The choice of evaluation metric heavily influences

4386-444: The company was founded, Andreessen Horowitz invested $ 100 million in venture capital with a $ 750 million valuation. In July 2015 GitHub raised another $ 250 million (~$ 314 million in 2023) of venture capital in a series B round . The lead investor was Sequoia Capital , and other investors were Andreessen Horowitz , Thrive Capital , IVP (Institutional Venture Partners) and other venture capital funds. The company

SECTION 50

#1732782436351

4472-517: The data that score highly: the features that have the largest projections in the lower-dimensional space are then selected. Search approaches include: Two popular filter metrics for classification problems are correlation and mutual information , although neither are true metrics or 'distance measures' in the mathematical sense, since they fail to obey the triangle inequality and thus do not compute any actual 'distance' – they should rather be regarded as 'scores'. These scores are computed between

4558-599: The diagonal of H . Another score derived for the mutual information is based on the conditional relevancy: where Q i i = I ( f i ; c ) {\displaystyle Q_{ii}=I(f_{i};c)} and Q i j = ( I ( f i ; c | f j ) + I ( f j ; c | f i ) ) / 2 , i ≠ j {\displaystyle Q_{ij}=(I(f_{i};c|f_{j})+I(f_{j};c|f_{i}))/2,i\neq j} . An advantage of SPEC CMI

4644-414: The feature f i in the globally optimal feature set. Let c i = I ( f i ; c ) {\displaystyle c_{i}=I(f_{i};c)} and a i j = I ( f i ; f j ) {\displaystyle a_{ij}=I(f_{i};f_{j})} . The above may then be written as an optimization problem: The mRMR algorithm

4730-420: The first year of being online, GitHub had accumulated over 46,000 public repositories, 17,000 of which were formed in the previous month. At that time, about 6,200 repositories had been forked at least once, and 4,600 had been merged. That same year, the site was used by over 100,000 users, according to GitHub, and had grown to host 90,000 unique public repositories, 12,000 having been forked at least once, for

4816-525: The first year: it pledges to cover payment processing costs and match sponsorship payments up to $ 5,000 per developer. Furthermore, users can still use similar services like Patreon and Open Collective and link to their websites. In July 2020, GitHub stored a February archive of the site in an abandoned mountain mine in Svalbard , Norway, part of the Arctic World Archive and not far from

4902-418: The importance of incorporating machine-learning techniques into liver-related prediction tools, especially within the context of the limited accuracy of MELD-Na when applied to patients with low scores. Transplantation further published a correspondence emphasizing this point. Chen & Asch 2017 wrote: "With machine learning situated at the peak of inflated expectations, we can soften a subsequent crash into

4988-588: The increased accuracy of using MELD-Plus vs. MELD in predicting early acute kidney injury after liver transplantation . MELD-Plus was validated by using Explorys. MELD-Plus was proposed as advantageous for patients with low MELD-Na scores. MELD 3.0 was introduced in 2021. A comparison between MELD 3.0, MELD-Plus, and other risk assessment scores in liver proposes approaches to more optimally allocate livers. United Network for Organ Sharing proposed that MELD-Na score (an extension of MELD) may better rank candidates based on their risk of pre-transplant mortality and

5074-525: The individual feature f i and the class c as follows: The redundancy of all features in the set S is the average value of all mutual information values between the feature f i and the feature f j : The mRMR criterion is a combination of two measures given above and is defined as follows: Suppose that there are n full-set features. Let x i be the set membership indicator function for feature f i , so that x i =1 indicates presence and x i =0 indicates absence of

5160-536: The launch of the GitHub Campus Experts program to train and encourage students to grow technology communities at their universities. The Campus Experts program is open to university students 18 years and older worldwide. GitHub Campus Experts are one of the primary ways that GitHub funds student-oriented events and communities, Campus Experts are given access to training, funding, and additional resources to run events and grow their communities. To become

5246-473: The least interesting variables. The other variables will be part of a classification or a regression model used to classify or to predict data. These methods are particularly effective in computation time and robust to overfitting. Filter methods tend to select redundant variables when they do not consider the relationships between variables. However, more elaborate features try to minimize this problem by removing variables highly correlated to each other, such as

SECTION 60

#1732782436351

5332-433: The media through a spokesperson, saying: GitHub is subject to US trade control laws, and is committed to full compliance with applicable law. At the same time, GitHub's vision is to be the global platform for developer collaboration, no matter where developers reside. As a result, we take seriously our responsibility to examine government mandates thoroughly to be certain that users and customers are not impacted beyond what

5418-422: The merit of a feature subset S consisting of k features: Here, r c f ¯ {\displaystyle {\overline {r_{cf}}}} is the average value of all feature-classification correlations, and r f f ¯ {\displaystyle {\overline {r_{ff}}}} is the average value of all feature-feature correlations. The CFS criterion

5504-421: The molecular structure of quartz glass platters, using a high-precision petahertz pulse laser, i.e. one that pulses a quadrillion (1,000,000,000,000,000) times per second. In March 2014, GitHub programmer Julie Ann Horvath alleged that founder and CEO Tom Preston-Werner and his wife, Theresa, engaged in a pattern of harassment against her that led to her leaving the company. In April 2014, GitHub released

5590-552: The number of samples < 10 ), the Hilbert-Schmidt Independence Criterion Lasso (HSIC Lasso) is useful. HSIC Lasso optimization problem is given as where HSIC ( f k , c ) = tr ( K ¯ ( k ) L ¯ ) {\displaystyle {\mbox{HSIC}}(f_{k},c)={\mbox{tr}}({\bar {\mathbf {K} }}^{(k)}{\bar {\mathbf {L} }})}

5676-399: The presence of another relevant feature with which it is strongly correlated. Feature extraction creates new features from functions of the original features, whereas feature selection finds a subset of the features. Feature selection techniques are often used in domains where there are many features and comparatively few samples (data points). A feature selection algorithm can be seen as

5762-409: The project accepts waitlist registrations. The Verge said that GitHub Sponsors "works exactly like Patreon " because "developers can offer various funding tiers that come with different perks, and they'll receive recurring payments from supporters who want to access them and encourage their work" except with "zero fees to use the program." Furthermore, GitHub offers incentives for early adopters during

5848-425: The redundancy between features. Peng et al. proposed a feature selection method that can use either mutual information, correlation, or distance/similarity scores to select features. The aim is to penalise a feature's relevancy by its redundancy in the presence of the other selected features. The relevance of a feature set S for the class c is defined by the average value of all mutual information values between

5934-404: The relevant feature set for a specific target variable whereas structure learning finds the relationships between all the variables, usually by expressing these relationships as a graph. The most common structure learning algorithms assume the data is generated by a Bayesian Network , and so the structure is a directed graphical model . The optimal solution to the filter feature selection problem

6020-422: The rest of GitHub, it includes free and paid service tiers. Websites generated through this service are hosted either as subdomains of the github.io domain or can be connected to custom domains bought through a third-party domain name registrar . GitHub Pages supports HTTPS encryption. GitHub also operates a pastebin -style site called Gist , which is for code snippets , as opposed to GitHub proper, which

6106-503: The sale bolstered interest in competitors: Bitbucket (owned by Atlassian ), GitLab and SourceForge (owned by BIZX, LLC) reported that they had seen spikes in new users intending to migrate projects from GitHub to their respective services. In September 2019, GitHub acquired Semmle , a code analysis tool. In February 2020, GitHub launched in India under the name GitHub India Private Limited. In March 2020, GitHub announced that it

6192-472: The set membership indicator function for feature f i ; then the above can be rewritten as an optimization problem: The combinatorial problems above are, in fact, mixed 0–1 linear programming problems that can be solved by using branch-and-bound algorithms . The features from a decision tree or a tree ensemble are shown to be redundant. A recent method called regularized tree can be used for feature subset selection. Regularized trees penalize using

6278-411: The site provides social networking -like functions such as feeds, followers, wikis (using wiki software called Gollum ), and a social network graph to display how developers work on their versions (" forks ") of a repository and what fork (and branch within that fork) is newest. Anyone can browse and download public repositories, but only registered users can contribute content to repositories. With

6364-415: The subset of features with the highest score discovered up to that point is selected as the satisfactory feature subset. The stopping criterion varies by algorithm; possible criteria include: a subset score exceeds a threshold, a program's maximum allowed run time has been surpassed, etc. Alternative search-based techniques are based on targeted projection pursuit which finds low-dimensional projections of

6450-509: The theoretically optimal max-dependency selection, yet produces a feature set with little pairwise redundancy. mRMR is an instance of a large class of filter methods which trade off between relevancy and redundancy in different ways. mRMR is a typical example of an incremental greedy strategy for feature selection: once a feature has been selected, it cannot be deselected at a later stage. While mRMR could be optimized using floating search to reduce some features, it might also be reformulated as

6536-569: The use of VPNs and IP proxies to access the site from sanctioned countries, as purchase history and IP addresses are how they flag users, among other sources. On December 4, 2014, Russia blacklisted GitHub.com because GitHub initially refused to take down user-posted suicide manuals. After a day, Russia withdrew its block, and GitHub began blocking specific content and pages in Russia. On December 31, 2014, India blocked GitHub.com along with 31 other websites over pro- ISIS content posted by users;

6622-454: The website and promotional materials; McEfee and various GitHub users have since created hundreds of variations of the character, which are available on The Octodex . Projects on GitHub can be accessed and managed using the standard Git command-line interface; all standard Git commands work with it. GitHub also allows users to browse public repositories on the site. Multiple desktop clients and Git plugins are also available. In addition,

6708-567: The workplace, and failure to enforce an agreement that his spouse should not work in the office." Preston-Werner subsequently resigned from the company. The firm then announced it would implement new initiatives and trainings "to make sure employee concerns and conflicts are taken seriously and dealt with appropriately." On July 25, 2019, a developer based in Iran wrote on Medium that GitHub had blocked his private repositories and prohibited access to GitHub pages. Soon after, GitHub confirmed that it

6794-557: The year, the number of repositories was twice as great, reaching 10 million repositories. In 2015, GitHub opened an office in Japan, its first outside of the U.S. On February 28, 2018, GitHub fell victim to the third-largest distributed denial-of-service (DDoS) attack in history, with incoming traffic reaching a peak of about 1.35 terabits per second. On June 19, 2018, GitHub expanded its GitHub Education by offering free education bundles to all schools. From 2012, Microsoft became

6880-497: Was acquiring npm , a JavaScript packaging vendor, for an undisclosed sum of money. The deal was closed on April 15, 2020. In early July 2020, the GitHub Archive Program was established to archive its open-source code in perpetuity. GitHub's mascot is an anthropomorphized "octocat" with five octopus-like arms . The character was created by graphic designer Simon Oxley as clip art to sell on iStock ,

6966-477: Was based on using unbiased approach toward discovery of biomarkers. In this approach, a feature selection machine learning algorithm observes a large collection of health records and identifies a small set of variables that could serve as the most efficient predictors for a given medical outcome. An example for a notable feature selection method is lasso (least absolute shrinkage and selection operator). A calculator capable of comparing MELD, MELD-Na, and MELD-Plus

7052-446: Was in line with Microsoft's business strategy under CEO Satya Nadella , which has seen a larger focus on cloud computing services, alongside the development of and contributions to open-source software. Harvard Business Review argued that Microsoft was intending to acquire GitHub to get access to its user base, so it can be used as a loss leader to encourage the use of its other development products and services. Concerns over

7138-452: Was now blocking developers in Iran , Crimea , Cuba , North Korea , and Syria from accessing private repositories. However, GitHub reopened access to GitHub Pages days later, for public repositories regardless of location. It was also revealed that using GitHub while visiting sanctioned countries could result in similar actions occurring on a user's account. GitHub responded to complaints and

7224-665: Was published in November 2019 in the European Journal of Gastroenterology & Hepatology . A study presented in June 2019 in Semana Digestiva (Vilamoura, Portugal) demonstrated that MELD-Plus was superior to assess mortality at 180 days vs. other liver-related scores in a population admitted due to hepatic encephalopathy . A study published in April 2018 in Surgery, Gastroenterology and Oncology reported on

7310-446: Was restricted to logged-in users, reportedly to mitigate spamming on the page of recent Gists. Gists' URLs use hexadecimal IDs, and edits to Gists are recorded in a revision history , which can show the text difference of thirty revisions per page with an option between a "split" and "unified" view. Like repositories, Gists can be forked, "starred", i.e., publicly bookmarked, and commented on. The count of revisions, stars, and forks

7396-477: Was then valued at approximately $ 2 billion. As of 2023, GitHub was estimated to generate $ 1 billion in revenue. The GitHub service was developed by Chris Wanstrath , P. J. Hyett , Tom Preston-Werner , and Scott Chacon using Ruby on Rails , and started in February 2008. The company, GitHub, Inc., was formed in 2007 and is located in San Francisco. On February 24, 2009, GitHub announced that within

#350649