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2. Announcements
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3. Functions Command Window or M File with Function Script File
displayHi.m
function z =
displayHi()
disp('Hi'); …
displayHi();

4. Functions
Function: A Discrete Piece of Code that Performs a Specific Operation or Task
Called procedure, module, method in other languages
Named with a Descriptive Identifier; Stored in FunctionName.m File
Called from Command Window or Scripts
When Called, Program Control (Execution) Is Transferred to the Function
Function Performs Required Tasks, and then Possibly Returns a Value
After Return from Function, Control Returns to the Statement Following the Function Call

5. Function Attributes Function Name: Identifier Used to Call Function
Function Parameter(s) or Argument(s): Value(s) Passed into Function for Use by Function Code
Function Return Value: Value Returned by Function Back to Calling Function

6. Function Parameters (Arguments)
May Pass as Many Parameters as Necessary to Function
A Copy of the Value of the Parameter Is Passed to the Function
Changing the Value of the Parameter in the Function Does Not Affect the Value of the Original Variable
This Is Called Pass-by-Value

7. Declaring a Function In .m File Format : Example : myFunction.m :
function resultVar = myFunction(parameter(s))
Example :
myFunction.m :
function result = myFunction(x)
result = x^2;
result = result^2;
Command Window :
>> c = myFunction(2)
c = 16

8. Another Function Example
myFunction2.m :
function result = myFunction2(x,y)
result = x^2 + y;
Command Window :
>> myFunction2(2,3)
ans = 7

9. Arrays Array – Set of Values with One Name MatLab Creation :
arrayName = [ 1,3,5 ];
Vector – One Dimensional Array
Matrix – Two Dimensional Array
Element – One Member (Value) in an Array
Offset or Subscript – location of an Element in and Array (in MatLab, starting with 1)
Row Vector - “Row” of Values
Column Vector - “Column” of Values

10. Creating Arrays – Row Vector
>> rowV(2)
ans = 3

11. Creating Arrays – Column Vector
>> colV = [ 2; 4; 6 ]
colV = 2 4 6
>> colV(3)
ans =

12. Transpose (') Operator
>> rowV'
ans = 1 3 5
>> colV'

13. Offsetting with Variable3
>> colV(offset)
ans = 6

14. Array Example >> for k = 1:10 newRow(k) = k^2; end

15. Colon Operator % [Start:Step:End] >> rowV = [10:5:50] rowV =
>> rowV = [10:5:49]
>> rowV = [10:15]

16. linspace() Function % linspace(Start, End, NumValues)
>> rowV = linspace(10,50,5)
rowV =

17. Adding Elements to Vectors
% linspace(Start, End, NumValues)
>> rowV = linspace(10,50,5)
rowV =
>> rowV(6) = 5555
>> newRowV(4) = 1000
newRowV =

18. Adding Vectors to Vectors
>> rowV = [ 1, 3, 5];
>> rowV2 = [ 7, 9, 11, 13];
>> rowVadd = [rowV, rowV2]
rowVadd =

19. Offset Errors >> rowVadd(8) Index exceeds matrix dimensions.
Subscript indices must either be real positive integers or logicals.
>> rowVadd(1.5)
>> rowVadd(8) = 77
rowVadd =