Transcript Program & Programming Languages

Program & Programming
Languages
Introduction to Programming
Programming is the process of writing a
computer program in a language that the
computer can respond to and that other
programmers can understand.
The set of instructions, data, and rules that
can be used to construct a program is called
a programming language.
The History of C
C evolved from two previous languages, BCPL,
and B. BCPL was developed in 1967 by Martin
Richards as a language for writing operating
systems software and compilers.
Ken Thompson modeled many features in his
language B after their counterparts in BCPL and
used B to create early version of the UNIX
operating system at Bell Laboratories in 1970 on a
DEC PDP-7 computer.
The C language was evolved from B by Dennis
Ritchie at Bell Laboratories in 1972.
History of C (cont.)
The rapid expansion of C over various types
of computers led to many variations.
These were similar, but often incompatible.
In 1989, the standard was approved.
– The document is referred to as ANSI/ISO
9899:1990.
Other High-Level languages
Hundreds of high-level languages have been
developed, but only a few have achieved
broad acceptance.
FORTRAN (FORmulaTRANslator) was
developed by IBM between 1954 and 1957
to be used for scientific and engineering
applications that require complex
mathematical computations.
Other High-Level languages (cont.)
COBAL (COmmon Business Oriented
Language) was developed in 1959 by a
group of computer manufactures and
government and industrial computer users.
– Today, more than half of all business software
is still programmed in COBAL.
PASCAL was designed at about the same
time as C. It was introduced for academic
use.
Other version of C
Other versions of C have been developed
through continuing research efforts at Bell
Laboratories.
– Gehani (Ge89) had developed Concurrent C - a C
superset that includes capabilities for specifying that
multiple activities can be performed in parallel.
Another C superset, namely, C++, was developed
by Bjarne Stroustup (St86) at Bell Laboratories.
– C++ provides capabilities to do object-oriented
programming. Objects are essentially reusable
software components that model items in the real
world.
The History of Matlab
Jack Little and Cleve Moler, the founders of The
MathWorks, recognized the need among engineers
and scientists for more powerful and productive
computation environments beyond those provided
by languages such as Fortran and C.
In response to that need in 1984, they combined
their expertise in mathematics, engineering, and
computer science to develop MATLAB®, a highperformance technical computing environment.
MATLAB combines comprehensive math and
graphics functions with a powerful high-level
language.
Object-Oriented Languages
One of the motivations for object-oriented languages has
been the development of graphical screens capable of
displaying multiple windows.
In such an environment each window on the screen can
conveniently be considered as an object, with associated
characteristics, such as color, position, and size.
Under an object orientation a program must first define the
objects it will be manipulating; this includes describing
both the characteristics of the object and the procedures
that can be used to manipulate and alter these
characteristics.
Algorithms and Procedures
As algorithms are central to Matlab’s
procedure-oriented side, it will serve us well
to understand what an algorithm is.
From a procedural point of view, before
writing a program, a programmer must
clearly understand what data is to be used,
the desired result, and the procedure to be
used to produce this result.
Algorithms and Procedures (cont.)
The procedure to be used is referred to as an
algorithm. More precisely, an algorithm is
defined as a step-by-step sequence of
instructions that describes how a
computation is to be performed.