In MATLAB, the for loop is used for repeating a set of statements for a fixed number of times. It is one of the most commonly used loops in programming. Here's the general syntax of how to use for loop in MATLAB:
for index = values
statement1
statement2
.
.
end
- index is a variable that takes on the values specified in values one after another.
- values can be a vector, a range of numbers specified using the : operator, or a combination of both.
Let's take a few examples to understand the usage of for loop in MATLAB:
Example 1 - Printing numbers in a range:
for i = 1:5
disp(i)
end
Output:
1
2
3
4
5
Here, variable
i takes on the values between 1 to 5 one after another, and for each value of i, the disp(i) statement is executed which displays the value of i on the screen.
Example 2 - Printing elements of a vector:
A = [10, 20, 30, 40, 50]
for i = 1:length(A)
disp(A(i))
end
Output:
10
20
30
40
50
Here,
length(A) returns the number of elements in the vector A. For each value of i between 1 to 5, the disp(A(i)) statement is executed which displays the element corresponding to that index position.
Example 3 - Looping through a matrix:
B = [1 2 3; 4 5 6; 7 8 9]
for i = 1:size(B, 1)
for j = 1:size(B, 2)
disp(B(i,j))
end
end
Output:
1
2
3
4
5
6
7
8
9
Here,
size(B, 1) and size(B, 2) return the number of rows and columns in the matrix B, respectively. The outer loop for i = 1:size(B, 1) goes through each row, and the inner loop for j = 1:size(B, 2) goes through each column in that row. The disp(B(i,j)) statement is executed for each element in the matrix.
These are just a few examples of how to use for loop in MATLAB. It is a versatile tool that is frequently used in programming to repeat a set of instructions multiple times.