script
Script (computer programming), a computer program written in a scripting language SCRIPT (markup), a text formatting language developed by IBM script (Unix), a command that records a terminal session Script, a description of procedural knowledge used in script theory, also used in artificial intelligence.
API
In computer programming, an application programming interface (API) is a set of subroutine definitions, protocols, and tools for building application software. In general terms, it is a set of clearly defined methods of communication between various software components. A good API makes it easier to develop a computer program by providing all the building blocks, which are then put together by the programmer. An API may be for a web-based system, operating system, database system, computer hardware or software library. An API specification can take many forms, but often includes specifications for routines, data structures, object classes, variables or remote calls. POSIX, Microsoft Windows API, the C++ Standard Template Library and Java APIs are examples of different forms of APIs. Documentation for the API is usually provided to facilitate usage.
Hadoop pipes
Hadoop pipes允许用户使用C++语言进行MapReduce程序设计。它采用的主要方法是将应用逻辑相关的C++代码放在单独的进程中,然后通过Socket让Java代码与C++代码通信。从很大程度上说,这种方法类似于Hadoop Streaming,不同之处是通信方式不同:一个是标准输入输出,另一个是socket。 Hadoop pipes设计原理
socket
A network socket is an internal endpoint for sending or receiving data at a single node in a computer network. Concretely, it is a representation of this endpoint in networking software (protocol stack), such as an entry in a table (listing communication protocol, destination, status, etc.), and is a form of system resource.
overfitting & underfitting
In statistics, overfitting is “the production of an analysis that corresponds too closely or exactly to a particular set of data, and may therefore fail to fit additional data or predict future observations reliably”.An overfitted model is a statistical model that contains more parameters than can be justified by the data.The essence of overfitting is to have unknowingly extracted some of the residual variation (i.e. the noise) as if that variation represented underlying model structure.
Underfitting occurs when a statistical model cannot adequately capture the underlying structure of the data. An underfitted model is a model where some parameters or terms that would appear in a correctly specified model are missing. Underfitting would occur, for example, when fitting a linear model to non-linear data. Such a model will tend to have poor predictive performance.
Overfitting and underfitting can occur in machine learning, in particular. In machine learning, the phenomena are sometimes called “overtraining” and “undertraining”.
threshold
the magnitude or intensity that must be exceeded for a certain reaction, phenomenon, result, or condition to occur or be manifested.
- the maximum level of radiation or a concentration of a substance considered to be acceptable or safe.
- a limit below which a stimulus causes no reaction.
- a level, rate, or amount at which something comes into effect.