1. ELEC 206 Computer Applications for Electrical Engineers Dr. Ron Hayne
Simple C++ Programs
ELEC 206
Computer Applications for Electrical Engineers
Dr. Ron Hayne
ELEC 330

2. Program Structure Object-Based Programming Program Structure Dev-C++

3. Object-Based Programming
Object-Oriented Programming
Identify the data requirements of the problem
How the data will be used in the program
Abstract Data Types
Class
Inheritance
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4. C++ Program /*-----------------------------------------------*/
/* Program chapter1_ */
/* */
/* This program computes the distance between */
/* two points */
#include <iostream>
#include <cmath>
using namespace std;
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5. C++ Program int main() { // Declare and initialize objects
double x1(1), y1(3), x2(4), y2(7),
side1, side2, distance;
// Compute sides of right triangle
side1 = x2 - x1;
side2 = y2 - y1;
distance = sqrt(side1 * side1 + side2 * side2);
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6. C++ Program // Print distance
cout << "The distance between the two points is "
<< distance << endl;
// Windows friendly exit
system("PAUSE");
return 0; }
/* */
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7. Program Structure Comments Preprocessor Directives Using Directive
/* */
/* Program chapter1_ */
// Declare and initialize objects
Preprocessor Directives
#include <iostream>
#include <cmath>
Using Directive
using namespace std;
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8. Program Structure Main Function Declarations object types
int main() { }
Declarations
object types
initial values
// Declare and initialize objects
double x1(1), y1(3), x2(4), y2(7),
side1, side2, distance;
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9. Program Structure Statements Return // Compute sides of right triangle
side1 = x2 - x1;
side2 = y2 - y1;
distance = sqrt(side1 * side1 + side2 * side2);
// Print distance
cout << "The distance between the two points is "
<< distance << endl;
Return
return 0;
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10. General Program Structure
preprocessing directives
int main() {
declarations;
statements; }
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11. Dev-C++ Bloodshed Software http://www.bloodshed.net/dev/devcpp.html
Dev-C beta 9.2 ( ) (9.0 MB) with Mingw/GCC 3.4.2
Download from:
SourceForge
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12. Dev-C++
New Source File
Compile
Run
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13. Windows Friendly Exit // Windows friendly exit system("PAUSE");
return 0;
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14. Summary
Object-Based Programming
Program Structure
Dev-C++
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15. Simple C++ Constants and Variables C++ Operators
Standard Input and Output
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16. Constants and Variables
Objects
Constants
Specific values
Variables
Memory locations
Identifiers
Begin with alphabetic character
Lowercase or uppercase letters (case sensitive)
Can contain digits (not first character)
Cannot be a keyword
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17. Scientific Notation Floating-Point Scientific Notation
2.5, , 15.0
Scientific Notation
25.6 = 2.56 x 101
= -4.0 x 10-3
Exponential Notation
25.6 = 2.56e1
= -4.0e-3
Mantissa
Precision
Example
Exponent
Range
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18. Numeric Data Types Integers Floating-Point short int long float double
long double
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19. Boolean Data Type Example Program Output
bool error(false), status(true);
cout << error << endl << status;
Program Output 1
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20. Character Data Type ASCII Character Constant Appendix B 7-bit binary
Single quotes
'A', 'b', '3'
Can be interpreted as character or integer
'3' != 3
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21. String Data String Constant String Objects Sequence of characters
Double quotes
"Fred", "C17"
String Objects
string class
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22. String Class /*-----------------------------------------------*/
/* This program prints a greeting */
/* using the string class */
#include <iostream>
#include <string> // Required for string class
using namespace std;
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23. String Class Hello Jane Doe! int main() {
// Declare and initialize two string objects.
string salutation("Hello"), name("Jane Doe");
// Output greeting.
cout << salutation << ' '
<< name << '!' << endl;
// Exit program.
return 0; }
Hello Jane Doe!
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24. Symbolic Constants Const Declared and initialized
Cannot be changed within the program
const double PI = acos(-1.0);
const double LightSpeed = e08;
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25. C++ Opeartors Assignment Operator Expression identifier = expression;
Constant, Object, Result of an Operation
double sum(10.5);
int x1(3);
char ch('a');
double sum;
int x1;
char ch;
sum = 10.5;
x1 = 3;
ch = 'a';
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26. Assignment Operator Multiple Assignments Type Conversion
x = y = z = 0;
Type Conversion
long double
double
float
long integer
integer
short integer
info lost
no loss
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27. Arithmetic Operators Unary Operators Binary Operators Positive +
Negative -
Binary Operators
Multiplication *
Division /
Modulus %
Addition +
Subtraction -
Precedence 2 3 4
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28. Mixed Operations Operation between values of different types
Value of lower type promoted
Cast Operator
(type)
Examples
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29. Expressions Distance = x0 + v0t + at2 Tension = ?
double distance, x0, v0, a, t;
distance = x0 + v0*t + a*t*t;
Tension = ?
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30. Increment and Decrement
Unary Operators
Increment ++
Decrement --
Prefix ++count
Postfix count--
Examples
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31. Abbreviated Assignment
Abbreviated Assignment Operators
x = x + 3; x +=3;
y = y * 2; y *=2;
Lowest Precedence (evaluate last)
a = (b += (c + d));
a = (b = b + (c + d));
b = b + (c + d);
a = b;
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32. Standard Output Standard Output Stream Manipulators
#include <iostream>
cout << "Hello " << name;
Stream Manipulators
#include <iomanip>
setprecision(n), fixed, scientific
setw(n), left, right, setfill(ch)
dec, oct, hex
endl
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33. Standard Output /*-----------------------------------------------*/
/* Program chapter2_ */
/* */
/* This program computes area of a circle. */
#include <iostream>
#include <iomanip>
#include <cmath>
using namespace std;
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34. Standard Output const double PI=acos(-1.0); int main() {
// Declare and initialize objects.
double radius(4.6777), area;
// Compute area
area = PI*radius*radius;
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35. Standard Output // Output results cout << setprecision(4)
<< "The radius of the circle is: "
<< setw(10) << radius << " centimeters"
<< endl;
cout << scientific
<< "The area of the circle is: " << setw(12)
<< area << " square centimeters" << endl;
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36. Standard Input Standard Input Whitespace used as delimiters
#include <iostream>
cin >> var1 >> var2 >> var3;
Whitespace used as delimiters
blanks, tabs, newlines
Values must be compatible with data type of objects
Stream Manipulators
#include <iomanip>
skipws, noskipws
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37. Summary Constants and Variables C++ Operators
Standard Input and Output
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38. Problem Solving Basic Functions Numerical Technique
Linear Interpolation
Problem Solving Applied
Wind-Tunnel Data Analysis
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39. Basic Functions Basic Math Functions Elementary Math Functions
#include <cmath>
Arguments are type double
Elementary Math Functions
fabs(x), abs(n)
sqrt(x), pow(x,y)
ceil(x), floor(x)
exp(x), log(x), log10(x)
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40. Basic Functions Trigonometric Functions
Angles in radians (180 degrees = π radians)
sin(x), cos(x), tan(x)
asin(x), acos(x), atan(x), atan2(y,x)
const double PI = acos(-1.0);
double angle_deg, angle_rad;
angle_deg = angle_rad*(180/PI);
angle_rad = angle_deg*(PI/180);
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41. Practice
velocity = sqrt(pow(v0,2) + 2*a*(x - x0));
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42. Other Functions Hyperbolic Functions Character Functions
sinh(x), cosh(x), tanh(x)
Character Functions
#include <cctype>
toupper(ch), tolower(ch)
isdigit(ch), isupper(ch), islower(ch)
isspace(ch), ispunct(ch)
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43. Interpolation
Use data points to determine estimates of a function f(x) for values of x that were not part of the original set of data
Cubic-spline Interpolation
Third-degree polynomial
Linear Interpolation
Straight line
a < b < c
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44. Example Data Set Estimate the temp at 2.6s Time, s Temp, deg F 0.0 1.0
20.0
2.0
60.0
3.0
68.0
4.0
77.0
5.0
110.0
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45. Problem Solving Applied
Wind-Tunnel Data Analysis
Problem Statement
Use linear interpolation to compute a new coefficient of lift for a specified flight-path angle
Input/Output Description
Data Point (a, f(a))
Data Point (c, f(c))
New Coefficient f(b)
New Angle (b)
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46. Problem Solving Applied
Hand Example
Estimate coefficient of lift at 8.7 degrees
Algorithm Development
Read coordinates of adjacent points
Read new angle
Compute new coefficient
Print new coefficient
Angle (degrees)
Coefficient of Lift 6
0.479 8
0.654 10
0.792 12
0.924 14
1.035
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47. Problem Solving Applied
/* */
/* Program chapter2_ */
/* */
/* This program uses linear interpolation to */
/* compute the coefficient of lift for an angle.*/
#include <iostream>
#include <iomanip>
#include <cmath>
using namespace std;
int main() {
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48. Problem Solving Applied
// Declare objects
double a, f_a, b, f_b, c, f_c;
// Get user input from the keyboard.
cout << "Use degrees for all angle measurements. \n";
cout << "Enter first angle and lift coefficient: \n";
cin >> a >> f_a;
cout << "Enter second angle and lift coefficient: \n";
cin >> c >> f_c;
cout << "Enter new angle: \n";
cin >> b;
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49. Problem Solving Applied
// Use linear interpolation to compute new lift.
f_b = f_a + (b-a)/(c-a)*(f_c - f_a);
// Print new lift value.
cout << fixed << setprecision(3);
cout << "New lift coefficient: " << f_b << endl;
// Windows friendly exit
system("PAUSE");
return 0; }
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50. Problem Solving Applied
Testing
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51. Summary Basic Functions Numerical Technique Problem Solving Applied
Linear Interpolation
Problem Solving Applied
Wind-Tunnel Data Analysis
End of Chapter Summary
C++ Statements
Style Notes
Debugging Notes
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