## MATLAB For Loop Tutorial

This is a tutorial on how to write and use For Loops in MATLAB. Table of contents below.

00:00 – Introduction
00:30 – General form
00:57 – Principle of operation
01:40 – Example 1
02:35 – Example 2
03:43 – Example 3
05:11 – Example 3 variation
06:01 – Example 4
07:54 – Example 5
10:48 – Example 6
12:53 – Conclusion

Brian Moya says:

How do you make a matrix using for loops

Carl Näsvall Sindeby says:

How do you repeat a statement such as disturbance(b)? I have a vector b I want to disturb it 10 times but I do not know how set up a for loop for it

Rose Roch says:

Hi…if I have row vector t=[0 0 -1 0 0] I have to sort in ascending order and then I have take 2 smallest value that is 0 and 0 then 0 will be -1 and other 0 will b 1.How to replace these elements and this will run till I get one positive number.

Ronnie wang says:

your result is from 1 to 55 , but my results are all 55

Rameez Ajaz says:

good one

nightclock626 says:

thank you man, you really opened an ocean upon me.
I have an exam tomorrow, please everyone, pray for me.

Frias M. says:

How would you collect the result in the for loop that satisfies a certain condition?

pop4ti says:

Great Tutorial. Thank you very much.

Matthew Skarbinski says:

Thank you for the awesome tutorial. I have an engineering final coming up and you helped immensely.

Diamond Blooded says:

Would this work for modelling a solar system? I need to find a way of having the angle which the earth is respective to the sun change constantly (lets say everyday day, so 365 times) so can I use this to change both the cos and sin value at the same time?

andrey montedori says:

Great video. I need to store in a vector generated in the n values ​​is.
For example:
for i = 1: 0.1: 2
x = 2 * i
end

X only stores the last value obtained in the repeat loop. I need everyone … If not mess up, like I do?

Priyabrata Halder says:

5:02 why “sum_a = sum(a) + a(ii)”? why not only “sum_a = sum(a) + ii”?

Emy Antonius says:

index must be a
positive integer or logical. this is a error that i get how kan i fix it?

Ather Cheema says:

Can we change two variables in a MATLAB at same time by a for loop? Suppose t=1:10 and g=21:30. I want formula to run first for t=1 and g=21 then the formula should run for t=2 and g = 21,22. Then the formula should use t=3 and g=21,22,23 and so on and so forth till it takes t = 10 and g=21:30 (now all value of g). Can you please elaborate it a bit.

Abhideep Singh says:

Please tell how do you put ‘%’ sign before each line after selecting them. thanks…

Clarensky Benoit says:

I don’t really understand the fourth example. can you help me with how the repetition is done?? like, what’s being done behind the scene by matlab for each output displayed. That would be of great help. Thanks beforehand.

Raoni Barros says:

Muito obrigado! it helps a lot!

Backyard Experimenter says:

Yeah Thanks, I have my first exam tomorrow morning and this helped me a lot

Monkey D Luffy says:

Hi. If i have n no. Of vector, can you pleas give me a for loop code that calculate the mean for this vectors and use it to calculate the covariance matrix.
Can any one help me in this pleas, Thank you so much.

The Boss says:

You are a GEM! I would hug you if i can! Im a First timer in Coding (any Coding) and you made me understand it! Thank you!

for the following code, I am having issues with psi1 not going through every variable in the vector. I only get one output for theta when I should have 10. What am I doing wrong?

psi=[0 0.125 0.25 0.5 0.75 1 1.5 2 3 4];

for psi1 = psi
r=linspace(-5,5,10);
theta=asin((psi1.*r)/((r.^2)-1));
x=r*sin(theta);
y=r*cos(theta);
figure(3)
plot(x,y)
grid on
hold on
end

Ronnie wang says:

Hi, Ilya,

why I use the same code
b = 1 : 10 ;
sum(b) = 0 ;
for i = 1 : length (b)
sum(b)= sum(b)+ b(i);
end
disp(sum(b))

and result shows a vector
for_loop
55 55 55 55 55 55 55 55 55 55

asfand khan says:

The natural numbers less than 10 that are multiples of 4 or 9 are 4, 8 and 9. Their sum is 21.Find the sum of all the multiples of 4 or 9 less than 1000. How would you find the matlab code for such a question? please help.

MOHSIN TANWEER says:

thanks helped us a lot

Abhideep Singh says:

a=1:10
sum_a=0
for i=1:10
sum_a=sum_a + a(i)
end

I tried doing little variation in the example shown at 4:35 (fabonacci series). if we write above code, why does the first answer is calculated as zero.