selection programming n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Selection Programming PowerPoint Presentation
Download Presentation
Selection Programming

Loading in 2 Seconds...

play fullscreen
1 / 20

Selection Programming - PowerPoint PPT Presentation


  • 95 Views
  • Uploaded on

Selection Programming. EE 100. Outline. introduction Relational and Logical Operators Flow Control Loops Update Processes. Introduction. Programs commands in MATLAB are executed in sequence.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Selection Programming' - sona


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
outline
Outline
  • introduction
  • Relational and Logical Operators
  • Flow Control
  • Loops
  • Update Processes
introduction
Introduction
  • Programs commands in MATLAB are executed in sequence.
  • The sequence can be altered using programming structures (control flow -if, switch-, repetition- for, while-).
  • Decision can be made using relational and logical expressions. (a check if a condition is met or not)
relational and logical operators
Relational and Logical Operators
  • For more information: help ops.
relational and logical operators1
Relational and Logical Operators
  • For relational and logical expressions:

Inputs: True is any nonzero number

False is 0 (zero)

  • Outputs: True is 1 (one)

False is 0 (zero)

  • An output array variable assigned to a relational or logical expression is identified as logical.
flow control
Flow Control
  • Simple if Statement
  • The general form of a simple if statement is:

if logical expression

commands

end

Example:

if d < 50

count = count + 1;

disp(d);

end

flow control1
Flow Control
  • Nested if Statements : general form

if logical expression

commands

if logical expression

Commands

end

end

flow control2
Flow Control
  • Example: Nested if Statements

if d < 50

count = count + 1;

if count > 10

disp(‘count > 10’);

end

end

flow control else and elseif clauses
General form

if logical expression

commands

else

commands

end

General form

if logical expression

commands

elseif logical expression

commands

elseif logical expression

Commands

else

Commands

end

Flow Control- else and elseif Clauses
flow control else and elseif clauses1
Flow Control- else and elseif Clauses
  • Example:

If average > 86

disp(‘Excellent’)

elseif average > 76

disp(‘Very good’)

elseif average > 68

disp(‘Good’)

else

disp(‘Ya 7aram- accepted’)

end

flow control switch structure
General form:

switch expression

case test expression 1

commands

case {test expression 2, test expression 3}

commands

···

otherwise

commands

end

Flow Control- Switch Structure
flow control switch structure1
Example:

d = floor(3*rand) + 1

switch d

case 1

disp( ’That’’s a 1!’ );

case 2

disp( ’That’’s a 2!’ );

otherwise

disp( ’Must be 3!’ );

end

Example:

d = floor(10*rand);

switch d

case {2, 4, 6, 8}

disp( ’Even’ );

case {1, 3, 5, 7, 9}

disp( ’Odd’ );

otherwise

disp( ’Zero’ );

end

Flow Control- Switch Structure
loops for loop
General form:

for index = j:k

statements

end

or

for index = j:m:k

statements

End

Floor (last − first)/increment + 1

for i = 1:5

disp(i)

end

for i = 1:2:5

disp(i)

end

Loops- for loop
loops while loop
General form

while condition

statements

end

Example:

count = 0;

While count < 5

disp (count)

count= count + 1;

end

Loops- while loop
loops while loop break
Loops- while loop - break
  • Example:

count = 0;

While count < 5

disp (count)

count= count + 1;

If count == 4

Break

end

end

avoiding loops
Avoiding loops
  • In general, loops should be avoided in Matlab, as they can significantly increase the execution time of a program.
  • The execution time increases as MATLAB allocate memory each time through the loop.
  • Usually avoid loops by vectorizing.
avoiding loops1
example: vectorizing

tic

n = 1:10000000;

s = sum( n );

toc

elapsed_time = 0.5300

example: loop

tic

s = 0;

for n = 1:10000000

s = s + n;

end

toc

elapsed_time = 23.6840

Avoiding loops
update processes
Update Processes
  • Many problems in science and engineering involve modeling a process where the main variable is updated over a period of time. In many situations, the updated value is a function of the current value.