CSMP III, or Continuous System Modelling Program IlI is an early scientific
computer software
Software is a set of computer programs and associated documentation and data. This is in contrast to hardware, from which the system is built and which actually performs the work.
At the lowest programming level, executable code consists ...
designed for modelling and solving
differential equation
In mathematics, a differential equation is an equation that relates one or more unknown functions and their derivatives. In applications, the functions generally represent physical quantities, the derivatives represent their rates of change, an ...
s numerically. This enables real-world systems to be simulated and tested with a computer.
Purpose
Since the early 1961s computer systems have been able to simulate real-world dynamic situations, such as the interaction between people in a public building such as an airport terminal. Models can be used to test the stresses imposed on an engineering structure without risk or construction cost. Modern uses include weather systems analysis and the effect on our planet Earth due to global warming. CSMP and its various versions were used extensively in the past when this software was first developed.
Structure
Like all computer programs its analytical and simulation programs are constructed from three general types of statements:
*''Structural statements,'' which define the model. They consist of
FORTRAN-like programming language statements, and functional blocks of program code (procedures) designed for repeat operations that frequently occur in a model definition.
*''Data statements,'' which assign numerical values to various changing parameters, constants, and
initial conditions.
*''Control statements,'' which specify options in assembly and execution of the program, and the choice of output of the results of the calculations performed.
Structural statements can make use of the operations of
addition
Addition (usually signified by the Plus and minus signs#Plus sign, plus symbol ) is one of the four basic Operation (mathematics), operations of arithmetic, the other three being subtraction, multiplication and Division (mathematics), division. ...
,
subtraction
Subtraction is an arithmetic operation that represents the operation of removing objects from a collection. Subtraction is signified by the minus sign, . For example, in the adjacent picture, there are peaches—meaning 5 peaches with 2 taken ...
,
multiplication
Multiplication (often denoted by the cross symbol , by the mid-line dot operator , by juxtaposition, or, on computers, by an asterisk ) is one of the four elementary mathematical operations of arithmetic, with the other ones being additi ...
,
division, and
exponentiation
Exponentiation is a mathematical operation, written as , involving two numbers, the '' base'' and the ''exponent'' or ''power'' , and pronounced as " (raised) to the (power of) ". When is a positive integer, exponentiation corresponds to re ...
, using the same notation and syntax rules as are used in FORTRAN. If, for example, the model includes the equation
:
the following statement will be used to define the variables and calculus performed:
x=6.0*Y/W+(Z-2.0)**2.0
Randomisation
Random variation to values can be added to some parts of the model to simulate unpredictable behaviour patterns in dynamic wind-loaded structures, such as high-rise buildings or aircraft wing designs.
Modern variations
The earlier CSMP III text-based programming language has been superseded by variations such as
APL and object oriented computer-language modelling versions of CSMP such as OOSCMP.
References
External links
* http://www.seas.ucla.edu/stenstro/r/r1
{{DEFAULTSORT:Csmp Iii
Domain-specific programming languages