Working with functions in matlab

Working with Functions in
MATLAB

Function prototype
• Functions in MATLAB starts with a keyword ‘function’.
• Second part of function syntax is outputs(return value),
unlike other programming lang, in MATLAB , a func can
return more than one value.
• Assignment operator.
• Then a valid function name(user defined, it should not
match any built-in function name or keyword)
• Lastly the arguments (inputs) to the function, this is
optional part.
• For example: function p=prime_num(a,b)

Simple function to find greatest of
three values.
Keyword output function name inputs
function o1 = greatest (a,b,c)
if((a>b)&&(a>c))
o1=a;
else if((b>a)&&(b>c))
o1=b;
else
o1=c;
end
end
Output:
greatest(10,4,26)
O1=26

Function with arguments and two or
more return values
outputs arguments
function [o1,o2]= myfunction(a,b,c)
o2=a*b*c
o1=a+b+c
End
output:
calling function, by typing function name in command window.
myfunction(5,6,2)
o2 = 60
o1 = 13
ans = 13
Note: To see all the outputs, we must not put semicolon after the output statement.
Note: if we put semicolon, we will see only the first output.

Function with arguments and no
return value
%function to find sum of even values between given range m-n
function [ ] = sum_of_even( m,n )
var temp;
temp=0;
for i=m:n
if(rem(i,2)==0)
temp=temp+i;
end
end
disp(temp); %display statement to show the result.
end
output:
sum_of_evem(1,10)30 ans
Note: since function is not returning any value so wecannot store the result into other
variable like we did in other function program.

Function within function
function [ sum ] = func_within_func( )
sum=0;
disp('we are in function "func_within_func"');
disp('now we will jump to other function, which is "sum_of_odd"');
calling function(sum_of_odd)
sum=sum_of_odd(1,10);
%Here we are finding sum of odd values between 1 and 10 %
end
Output: we are in function "func_within_func"
now we will jump to other function, which is "sum_of_odd"
ans =
25

Storing value returned by function into
other variable.
function big=greater(a,b)
if(a>b)
big=a;
else
big=b;
end
End
Output:
n=greater(45,67)
n=5
>>n*n %reused the function result without calling function
ans =25

Points to Remember
• Function name and file name must be same.
• Unlike other programming languages, Function in MATLAB can return more than
one value.
• Syntax: function outputs=function_name(inputs)
• There is no starting and ending curly braceS to enclose the body of function,
instead, there is an end statement which signifies end of function.
• For example function o1=greatest(a,b,c)
• Other example: function [o1,o2] = 2greatest(a,b,c,d,e)
• To run a function we type a function name with valid arguments in command
window area.
• If function returns two or more ouputs,to see all the outputs, we must not put
semicolon after the output statement. Note: if we put semicolon, we will see only
the first output.
• We can store the value returned by function into other variable using assignment
statement like: big_value=greatest(5,4,7,9,13) then print variable big_value.
Advantage is we can use the function result again and again by using variable
name instead of function call.

Working with functions in matlab

Working with functions in matlab

More Related Content

What's hot

Similar to Working with functions in matlab

More from harman kaur

Recently uploaded

Working with functions in matlab