⊿ Point. {R} Glossary. ◢ Keyword: V. ◥ University. {q} PhD. {tr} Training. ⚫ UK. ↂ EndNote. ☝️ Weerakkody. Variable. Variable. From Wikipedia, the free encyclopedia Variable may refer to: Dependent and independent variables. Variables used in an experiment or modelling can be divided into three types: "dependent variable", "independent variable", or other.
The "dependent variable" represents the output or effect, or is tested to see if it is the effect. The "independent variables" represent the inputs or causes, or are tested to see if they are the cause. Other variables may also be observed for various reasons. Use Calculus gives a relation between y and x. Statistics In a statistics experiment, the dependent variable is the event studied and expected to change whenever the independent variable is altered.[1] Data mining In data mining tools (for multivariate statistics and machine learning), the depending variable is assigned a role as target variable (or in some tools as label attribute), while a dependent variable may be assigned a role as regular variable.[2] Known values for the target variable are provided for the training data set and test data set, but should be predicted for other data. Modelling. Control variable. The term control variable has different meanings, depending on the area/place in which it is used.
The control variable is something that is constant and unchanged in an experiment. Further, a control variable strongly influences values; it is held constant to test the relative impact of independent variables. Experimental examples[edit] In scientific experimentation, a control variable is the one element that must not be changed throughout an experiment because it also affects the other independent variables being tested, thus affecting the outcome of the experiment.
For example, in the experimental verification of Boyle's law (P = T / V), where Pressure, Temperature, and Volume are all variables; to test the resultant changes to any of these variables requires at least one of the other variables to be kept constant. This is in order to see comparable experimental results in the remaining variables. In control theory[edit] In computer programming[edit] Examples[edit] See also[edit] Multivariable calculus (multiple variables) Typical operations[edit] Limits and continuity[edit] A study of limits and continuity in multivariable calculus yields many counter-intuitive results not demonstrated by single-variable functions. For example, there are scalar functions of two variables with points in their domain which give a particular limit when approached along any arbitrary line, yet give a different limit when approached along a parabola. For example, the function approaches zero along any line through the origin. , it has a limit of 0.5.
Continuity in each argument is not sufficient for multivariate continuity: For instance, in the case of a real-valued function with two real-valued parameters, , continuity of in for fixed and continuity of does not imply continuity of . It is easy to check that all real-valued functions (with one real-valued argument) that are given by are continuous in (for any fixed ). Are continuous as is symmetric with regards to and . Itself is not continuous as can be seen by considering the sequence if. Variable and attribute (research) From Wikipedia, the free encyclopedia Science and research term While an attribute is often intuitive, the variable is the operationalized way in which the attribute is represented for further data processing. In data processing data are often represented by a combination of items (objects organized in rows), and multiple variables (organized in columns). Values of each variable statistically "vary" (or are distributed) across the variable's domain.
A domain is a set of all possible values that a variable is allowed to have. Semantically, greater precision can be obtained when considering an object's characteristics by distinguishing 'attributes' (characteristics that are attributed to an object) from 'traits' (characteristics that are inherent to the object). Examples[edit] See also[edit] Notes[edit]