haseeb tariq
TRANSCRIPT
SUBJECT: MATLAB
INSTRUCTOR:Mr. AFZAL
Group Leader:Saad Sharif Saleemi
ROLL No.UW-13-ME-BSc-002
DEPARTMENT OF MECHANICAL ENGINEERING
GROUP MEMBERS
Sohail Tariq UW-13-ME-BSc-004
Ramsha Humayun UW-13-ME-BSc-006
Ali Hamza UW-13-ME-BSc-008
Munawar Riaz UW-13-ME-BSc-010
Muhammad Umer UW-13-ME-BSc-012
Haseeb Tariq UW-13-ME-BSc-014
Yousaf Ali UW-13-ME-BSc-016
Maryam Arshad UW-13-ME-BSc-018
Talha Shahid UW-13-ME-BSc-020
Script in matlab
M-files
Functions
Built-in functions
User defined functions
Loops
Types of loops
Implementation of loops
M-FILE:
MATLAB can execute a sequence of statements stored in
files. These are called M-files because they must have
the file type .m as the last part of their filename.
Much of our work with MATLAB will be in creating and
refining M-files. M-files are usually created using your
text editor or with MATLAB’s M-file.
There are two types of M-files: script files and function
files
Script files:
Scripts do not accept input arguments or return output arguments. They operate on data in the workspace.
Opening M-file
Go to NEW> M-FILE to start a new M-file.
Editor screen pops out.
Type this in editor:
b=4
a=b+4
save it as filename.m
execute to show result
“a=8”
We’ve just created a MATLAB script file.
Script files:
A script file consists of a sequence of normal MATLAB statements.
Script files are especially useful for analysis and design problems that
require long sequences of MATLAB commands.
With script file written using a text editor or word processor, the file can
be invoked by entering the name of the m-file, without the extension.
Statements in a script file operate globally on the workspace data.
Normally, when m-files are executing, the commands are not displayed on
screen. The MATLAB echo command can be used to view m-files while they
are executing.
When we invoke a script, MATLAB simply executes the
commands found in the file. Scripts can operate on existing
data in the workspace, or they can create new data on which to
operate. Although scripts do not return output arguments, any
variables that they create remain in the workspace, to be used
in subsequent computations. In addition, scripts can produce
graphical output using functions like plot.
Builtin Functions
Exponential
exp(x)
sqrt(x)
Logarithmic
log(x) natural logarithm ln
log10(x)
log2(x)
Builtin continued
numeric ceil(x) round to nearest integer towards +∞
fix(x) round to nearest integer towards 0
floor(x) round to nearest integer towards - ∞
round(x) round to nearest integer
sign(x) +1, 0 or -1
rem(x,y) Finds remainder of x/y
complex abs(x) absolute value
angle(x) in complex plane
conj(x)
imag(x)
real(x)
Builtin continued
Trigonometric and their inverse
cos(x) acos(x)
sin(x) asin(x)
tan(x) atan(x)
cot(x) acot(x)
csc(x) acsc(x)
sec(x) asec(x)
Builtin Functions continued
Hyperbolic and their inverse
cosh(x) acosh(x)
coth(x) acoth(x)
csch(x) acsch(x)
sech(x) asech(x)
sinh(x) asinh(x)
tanh(x) atanh(x)
Remarks
All trigonometric functions require the use of radians and not degrees
All built in functions can also be used with complex numbers.
Builtin Functions for vectors
max(x) returns largest value in vector x
[a,b] = max(x) returns largest value in a and index where
found in b
max(x,y) x and y arrays of same size, returns vector
of same length with lager value from corresponding positions in x and y
same type of functions are available for min
User defined functions
Similar to script files except that
temporary variables remain local
function use standardized input and output parameters
Script files good for quick work
Functions can be used over and over again
Matlab code for user defned
function
function z = fun(x,y)
X and y values are defined above in parameters of the function
z = 3*x + 6*y.^2 ;
Loops
In computer programming, a loop is a sequence
of instruction s that is continually repeated until a
certain condition is reached. Typically, a certain process
is done, such as getting an item of data and changing it,
and then some condition is checked such as whether a
counter has reached a prescribed number.
Loops
In Matlab, the loop must be completed by the word end.
For Loop
For loop is useful when the number of iterations that a
condition is run is known. for loop will be executed a fixed
number of times
While loops
A while loop will continue to be repeated until some
condition is satisfied While loop is useful when the number of
iterations is unknown.
For Loops
For loops require explicit values in order to
function. These values can be predefined or stated
within the loop.
The Matlab syntax is:
for value=start:counter:finish
[commands]
end
For loop
The basic MATLAB loop command is for and it uses the idea of repeating an Operation for all the elements of a vector.
SIMPLE PROGRAM:
>> for j=1:4
j
end
OUTPUT:
j = 1
j = 2
j = 3
j = 4
Factorial program using for
loop
FACTORIAL PROGRAM:
fact = 1;
for i = 2:6
fact = fact * i
end
OUTPUT:
fact = 1;
i=2; fact = fact * i; At this point fact is equal to 2
i=3; fact = fact * i; At this point fact is equal to 6
i=4; fact = fact * i; At this point fact is equal to 24
i=5; fact = fact * i; At this point fact is equal to 120
i=6; fact = fact * i; At this point fact is equal to 720
While loop
Suppose we now want to repeat a loop until a certain
condition is satisfied.
This is achieved by making use of the MATLAB command
while, which has
the syntax.
SYNTAX:
while (condition)
commands...
end.
Example for while loop
Consider this loop:
k = 0;
while k < 10
k = k + 2
end
How many times will the loop be executed?
Initially, k = 0, so the loop is entered
Pass #1: k = 2, so execution continues
Pass #2: k = 4, so execution continues
Pass #3: k = 6, so execution continues
Pass #4: k = 8, so execution continues
Pass #5, k = 10, so k is not less than 10 and execution ends
Do While Loop
In most computer programming languages, a do while
loop is a control flow statement that executes a block
of code at least once, and then repeatedly executes the
block, or not, depending on a given Boolean condition
at the end of the block
Examples
Intermediate results of statements within a repeat and
while loop are not printed to the screen:
i := 1:
s := 0:
while i < 3 do
s := s + i;
i := i + 1;
end_while
example
Above, only the return value of the loop is displayed. Use
print to see intermediate results:
i := 1:
s := 0:
while i < 3 do
print("intermediate sum" = s);
s := s + i;
i := i + 1;
s
end_while