Operator concatenation

Ka,K% - secret encryption keys EK - encryption with key K II concatenation operator... 

A[2], ZCat[0] and Reg File[3] are examples of bit-selects. The concatenation operator,, is used to generate a bigger array. 

VBA operators include the arithmetic operators (+, -,, /, the text concatenation operator ( ), the comparison operators (=, <, >, <=, >=, <>) and the Boolean or logical operators, which are discussed later. 

Excel Tip. Be sure to leave a space on either side of the concatenation operator ... 

The Sub procedure shown in Figure 15-1 reads values from worksheet cells and writes them to elements of a VBA array by means of a loop. Either the Cells method or the Range method can be used in the example that follows, the Range method is used, with the concatenation operator, to access the appropriate cell in the range. In this example the values to be copied are in column A, beginning in row 2. To illustrate an additional point, the values extend down to a row that must be determined by the VBA code. 

The system being described in Figure 2-3 is a Kalman filter, a realtime controller consisting of several loops implementing matrix multiplication and other operations. The input to the system is the y array, and the output is the v array. First to be described are the carriers that will take part in the computation. Second, the procedures that specify the actions on the variables are listed. In this case, there is only one procedure (filt) consisting of several nested, labeled blocks and repeat loops. The "Imain)" qualifier indicates that filt is the starting point for execution. A quote mark (") indicates a hexadecimal constant, labeled blocks are named with a colon-equal ( =), and the is the binary concatenation operator. 

Box 5.2 demonstrated how elements and slices of arrays can be used in assignment statements. The concatenation operator and shift operators can also be used in the same way as was illustrated in Box 5.3. Any of these manipulation techniques can be combined with others to make a more complex expression. For example/ using (he declarations from Box 5.2, arrays could be constructed as follows ... 

Note the use of parenthesis around the logical function. Without these around the And operation the expression will be incorrectly evaluated. Both these expressions contain strings of characters enclosed in double quotes that are used to represent bit patterns. These examples illustrate binary representations but octal and hexadecimal formats may also be used (see Box 5.5). Using the concatenation operator to construct array expressions is only one approach. It is also possible to use aggregate expressions that take the form ... 

The concatenation operator is also classed as an adding operator. This was covered in Chapter 5. The adding operators have the lowest precedence and the miscellaneous operators have die highest. 

The symbol is the concatenation operator, it appends the value of the variable Average to the preceeding text. 

Each of these operators is unitary U —t) = U t). Updating a time step with the propagator Uf( At)U At)Uf At) yields the velocity-Verlet algorithm. Concatenating the force operator for successive steps yields the leapfrog algorithm ... 

Since the notation does not always make it apparent, we should note that a and c play operationally similar roles as macrostate labels Together they identify the distinct sets of equilibrium macroscopic properties emerging from the equilibrium distribution, Eq. (1). For some purposes we will find it useful to concatenate the two labels into a single grand macrostate label... 

Finally, many chemometricians use matrices. Matlab (see Section A.5) is better than Excel for developing sophisticated matrix based algorithms, but for simple applications the matrix operations of Excel can also be translated into VBA. As discussed in Section A.4.4.2, this is somewhat awkward, but for the specialist programmer there is a simple trick, which is to break down the matrix expression into a character string. Strings can be concatenated using die sign. Therefore, the expression... 

Note that the concatenates lines into a single statement. By generalising, it is easy to incorporate flexible matrix operations into VBA programs, and modifications of this principle could be employed to produce a matrix library. 

There is only one text operator the (ampersand ) symbol. It is used to concatenate text, or text and variables. For example, if cell G256 contains the value 2001, the formula ="Chemical Inventory for " G256 displays Chemical Inventory for 2001. You ll encounter many other uses of the operator in the chapters that follow. 

Excel provides a wide range of worksheet functions that operate on text. You are already familiar with the operator, to concatenate text or text and values. Most of Excel s text functions select or modify one or more characters within a text string. 

Like cadastral maps, the experimental plots of agricultural research stations cannot begin to represent the diversity and variability of farmers fields. The researchers must operate on the basis of standard, normal-range assumptions about soil, field preparation, weeding, rainfall, temperature, and so on, whereas each farmer s field is a unique concatenation of circumstances, actions, and events, some of which are knowable in advance (soil composition) and some of which are out of anyone s hands (the weather). The interactions among these and other variables are at least as important as the status of each thus the effects of an early monsoon on rocky soil that has just been weeded are different from those of an early monsoon on waterlogged land that has not been weeded. 

Blending This operator simply concatenates two parents to produce one offspring whose length is the sum of those of the two parents. 

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