1. Electrical and Computer Engineering Department SUNY – New Paltz
Computer Simulation
“Lecture 2”
Electrical and Computer Engineering Department
SUNY – New Paltz
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2. Operators, Expressions, Statements
Arithmetic operations between two scalars
Operation Algebraic form MATLAB
Addition a + b a + b
Subtraction a - b a - b
Multiplication a × b a * b
Right division a/b a / b
Left division b/a a \ b
Power ab a ^ b
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3. Operators, Expressions, Statements (Exercises)
Write MATLAB statements to evaluate:
(3.01 – 2.55)x(.123/.001)/( )
(1+ .09)10
sin(15º)
( ) 2 / ( ) 3
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4. Precedence of arithmetic operations
Precedence Operator 1 Parentheses 2 Power, left to right 3 Multiplication and division, left to right 4 Addition and subtraction, left to right
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5. Exercise Evaluate the following arithmetic expressions: A= 2/4^2*2+1\4
B=1/2^2*2/4
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6. Arithmetic operations on arrays
Arithmetic operators that operate element-by-element on arrays
Operator Description
.* Multiplication
./ Right division
.\ Left division
.^ Power
Examples:
a = [2 4 8]; * a = ?
b = [3 2 2]; a .^ 2 = ?
a .* b = ?
a ./ b = ?
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7. Arithmetic operations on arrays (Exercises)
Form a vector that contains the squares of numbers between 1 and 5.
Form a vector that contains the cubes of numbers between -10 and 10.
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8. Statements, Commands and Functions
Statements: s = u * t - g / 2 * t .^ 2;
Functions: sin(x), plot(x)
Commands: clc, help, clear
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9. Exercise Execute the following program from Command Window:
t = 0: 0.1: 2*pi;
x = cos(t);
y = sin(t);
plot(x,y);
Run the same program from a “.m” file. Save your file as “myex1.m”
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10. Vectorization of Formulae 1- Use a calculator
Initial deposit= 750; Interest rate = 0.09; Calculate account value for 3 years based on compound interest: End of the first year: End of the second year: End of the third year:
*.09 = 817.5
*.09 =
*.09 =
( *.09) + ( *.09)*.9 =
( *.09)*( ) = 750 * ( )2
*.09 =
750 * ( )2
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11. Vectorization of Formulae 2- Case of Scalar
Write a sequence of MATLAB statements to find and display the account value after 10 years.
Initialization
A = 750;
r = 0.09;
n = 10;
B = A * (1 + r) ^ n;
User Inetrface (I/O)
disp( [A B] )
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12. Vectorization of Formulae 3- Case of Multiple Investment
Write a sequence of MATLAB statements to find the account value after 10 years for 5 different deposits:
A = [ ];
r = 0.09;
n = 10;
B = A .* (1 + r) ^ n;
disp( [A’ B’] )
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13. Output disp( variable ) {variable could be numerical or textual}
disp( ’Pilate said, ’’What is truth?’’’ );
disp( [x y z] )
disp( [’The answer is ’, num2str(x)] );
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14. Output /Exercise
Write a MATLAB program (‘mysum.m’) that receives the length of 2 the sides (e.g. 3 and 4) and prints out the length of its hypotenue as ‘Hypotenuse = 5’
clear all
clc
a = input(‘Enter Length of Side 1: ’);
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15. Types of Variables Fixed Point (int): Floating Point (float):
Unsigned integer (0, 1, 2, …)
Integer ( …, -3, -2, -1, 0, 1, 2, 3, …)
Floating Point (float):
Single ( example: )
Double (example: )
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16. format 1234567890 is displayed as 1.2346e+009
mantissa is between 1 and
format short - 4 digits after the decimal point. For example, 3.1416
format short e - Floating-point format, with 4 digits after the decimal point. For example, 3.1416e+00
format long - Scaled fixed-point format with 15 digits after the decimal point for double; and 7 digits after the decimal point for single. For example, 
format long e - Floating-point format, with 15 digits after the decimal point for double; and 7 digits after the decimal point for single. For example, e+00.
format long g - Fixed- or floating-point, whichever is more readable, with 14 to 15 digits after the decimal point for double; and 6 or 7 digits after the decimal point for single. For example, 
format short g - Fixed- or floating-point, whichever is more readable, with 4 digits after the decimal point. For example, 
format compact, format hex, format rat, format bank
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17. Format (exercise)
Put MATLAB in each of the following format and display the number and .3
format short
format short e
format long g –
format short g –
format rat
Format bank
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