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Introduction to R/Python Programming
Published in Nailong Zhang, A Tour of Data Science, 2020
In mathematics, a variable is a symbol that represents an element, and we do not care whether we conceptualize a variable in our mind, or write it down on paper. However, in programming a variable is not only a symbol. We have to understand that a variable is a name given to a memory location in computer systems. When we run x = 2 in R or Python, somewhere in memory has the value 2, and the variable (name) points to this memory address. If we further run y = x, the variable y points to the same memory location pointed to by (x). What if we run x=3? It doesn’t modify the memory which stores the value 2. Instead, somewhere in the memory now has the value 3 and this memory location has a name x. And the variable y is not affected at all, as well as the memory location it points to.
Governing Equations
Published in Dalia E. E. Khalil, Essam E. Khalil, Sprinklers and Smoke Management in Enclosures, 2020
Dalia E. E. Khalil, Essam E. Khalil
The governing equations of a mathematical model describe how the values of the unknown variables (i.e., the dependent variables) change when one or more of the known (i.e. independent) variables change. A mathematical model describes a system using mathematical concepts and language. The process of developing a mathematical model is termed mathematical modeling. Mathematical models are used in natural sciences (such as physics, biology, earth science, chemistry) and engineering disciplines (such as computer science, electrical engineering), as well as in the social sciences (such as economics, psychology, sociology, political sciences). A model may help to explain a system and study the effects of different components, as well as to make predictions about behavior. A mathematical model usually describes a system by a set of variables and a set of equations that establish relationships between the variables. Variables may be of many types; real or integer numbers, Boolean values or strings. The variables represent some properties of the system, for example, measured system outputs often in the form of signals, timing data, counters, and event occurrence (yes/no). The actual model is the set of functions that describe the relations between the different variables.
Computer programming for musical applications
Published in Kirk Ross, Hunt Andy, Digital Sound Processing for Music and Multimedia, 2013
Notice the following features of this algorithm: At the top of the code is a variable called ‘count’. A variable is a named entity which can temporarily store data. In this case the data is an int (an integer, or whole number). The line count=0 sets the initial value of ‘count’ to zero.The line while (count < 4) denotes the start of a’loop’. All the code between the curly brackets {and} will be continually repeated while the variable ‘coun’ contains a value less than 4.The line count = count + 1; adds 1 to the value of count each time around the loop. In this way ‘count’ starts off as 0, increases to 1, then 2, then 3. At this point the loop has gone around four times. As count increases to 4, the line while (count < 4) is no longer true and so the loop cannot go round again. Thus ‘count’ can be considered to be a loop control variable as its value determines how long the loop should run for.
FloVasion: Towards Detection of non-sensitive Variable Based Evasive Information-Flow in Android Apps
Published in IETE Journal of Research, 2022
Bharat Buddhadev, Parvez Faruki, Manoj Singh Gaur, Shubham Kharche, Akka Zemmari
Algorithm 3.2 illustrates data-flow evasion via non-sensitive variables deploying runtime exception. It converts sensitive information (e.g. IMEI, IMSI) to binary data and stores it inside variable X. Another string variable R stores the binary value of variable X. A variable P is initialized with value “1”. At line number 5, we scan the variable X. At kth iteration, variable p is divided by X[i]. If the operation generates “Arithmetic Exception”, variable R is appended with “zero” and p is initialized with “1” at line number 10 and 11. If there is no exception, then R is appended by value “1”. Finally, variable R is returned at the end of the loop at line number 13 (Figure 2).
Part segregation based on particle swarm optimisation for assembly design in additive manufacturing
Published in International Journal of Computer Integrated Manufacturing, 2019
Lohithaksha M. Maiyar, Sube Singh, Vittal Prabhu, Manoj Kumar Tiwari
The decision variable is an integer variable that takes values in between one and maximum number of shapes in the object. The value of is evaluated as a function of using the part segregation algorithm described in the next section. Thus, for every , there exists where and are candidate solutions to the proposed problem. The binary decision variable captures the support material allocation plan for every merge in final parts set .
Parallel machine scheduling with tool loading: a constraint programming approach
Published in International Journal of Production Research, 2018
Burak Gökgür, Brahim Hnich, Selin Özpeynirci
Another local consistency is bound consistency (BC), which requires the domains of the variables to be represented by an interval. For integer variables, the values can obey a natural total order, therefore the domain can be represented by an interval whose lower bound is the minimum value and the upper bound is the maximum value in the domain. Given a constraint C, a bound support on C is a tuple on var(C) that assigns to each integer variable a value between its minimum and maximum. A value for an integer variable is bound consistent withC iff there exists a bound support assigning this value to this variable. A constraint C is bound consistent (BC) iff for each integer variable , its minimum and maximum values belong to a bound support.