CSMP III, or Continuous System Modelling Program IlI is an early scientific
computer software
Software consists of computer programs that instruct the Execution (computing), execution of a computer. Software also includes design documents and specifications.
The history of software is closely tied to the development of digital comput ...
designed for modelling and solving
differential equations 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
In mathematics and particularly in dynamic systems, an initial condition, in some contexts called a seed value, is a value of an evolving variable at some point in time designated as the initial time (typically denoted ''t'' = 0). Fo ...
.
*''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), divis ...
,
subtraction
Subtraction (which is signified by the minus sign, –) is one of the four Arithmetic#Arithmetic operations, arithmetic operations along with addition, multiplication and Division (mathematics), division. Subtraction is an operation that repre ...
,
multiplication
Multiplication is one of the four elementary mathematical operations of arithmetic, with the other ones being addition, subtraction, and division (mathematics), division. The result of a multiplication operation is called a ''Product (mathem ...
,
division, and
exponentiation
In mathematics, exponentiation, denoted , is an operation (mathematics), operation involving two numbers: the ''base'', , and the ''exponent'' or ''power'', . When is a positive integer, exponentiation corresponds to repeated multiplication ...
, 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
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Domain-specific programming languages