Variable declaration

Declares variables as state/derivative pairs. Also makes routine a sub-model. 

All common variable types are supported. It is best to declare variables, using either the Dim or Redim statement, which can occur anywhere in a procedure. Arrays must be declared. There are some leftovers from older versions of the language whereby a variable that ends in % is automatically an integer, for example i%, and a variable ending in a character, for example n. However, it is not necessary for these variable types to end in these characters providing they are specifically declared, e.g. 

Variables (reg and integer types) declared locally within an always statement do not infer flip-flops. This may potentially lead to a functional mismatch between the Verilog HDL model and the synthesized netlist. Here is an example of a locally declared variable Temp that does not get inferred as a flip-flop. 

However, a potential for mismatch exists between the design model and its synthesized netlist if the order of the above statements are reversed. This is because no flip-flops are inferred for locally declared variables. Here is such a model. 

The synthesized netlist is the same as in Figure 2-48. Notice that on every clock edge, NextState always get the value of Temp assigned in the previous clock cycle, but not so in the synthesized netlist. The recommendation here is to avoid using locally declared variables in this fashion. Hopefully a synthesis tool will issue a warning if no flip-flops are inferred for Temp. 

Locally Declared Variable, 60 Variable Assigned Before Use, 61 Use Before Assigned, 62... 

AUTOEXEC. BAT Used to run particular programs during startup. Also declares variables (such as search paths). 

The equation is stated using the declared variables and constants, the operators (+, -, >, etc.) and GAMS functions (sine, sum, etc.). 

Alternatively, for real-valued variables, this can be accomplished by defining equations that incorporate the bounds on the variables. However, the use of re-declared variables provides for a more concise input file. The key words to define the bounds on a variable are... 

Variable Declarations. Variables can be declared over sets (that is, with sets as their elements). In Example 10.8, the variable Rik is declared R(HOT,lNT), is declared... 

Sheets("Sheet1").Select Range("A13", "G120").Clear Declare variables Dim i, feedstage, N As Integer... 

Table 4.1 contains a C+-b computer program that applies the Numerov method to the harmonic-oscillator Schrodinger equation. The fifth and sixth lines declare variables as either integers or double precision, m is the number of intervals between x o and x max and equals (Xr,max Xrfl)/s. cout and cin provide for output to the computer screen and input to the variables of the program. Note the colon at the end of line 13 and the semicolons aftermost other lines. The three lines beginning with g[0]=, g[1 ]=, and g[i -b 1 ]= contain two times the potential-energy function. These lines must be modified if the problem is not the harmonic oscillator. If there is a node between two successive values of x, then the if/r values at these two points will have opposite signs (see Prob. 4.45) and the statement nn=nrn-1 will increase the nodes counter nn by 1. 

The state section declares state variables names and domains. Values of variable Status are in user defined domain FailureType that is the enumeration ok. lost, erroneous. These values denote the failure status of a node. The correct value is used when the node is working correctly, the lost value is used when the node is not producing any output, the value erroneous is used when the node is producing an output whose value deviates from what is expected. The flow section declares variables that are used to model data exchanged with interfaced components, the FailureType domain is used. 

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