MATLAB for Engineers - Introduction to for Loops (Part 3 of 4): Indexing and Storage in Arrays

A for loop is a loop structure for repeating a calculation a pre-defined number of times. In this video, we'll use a for loop to store data inside of an array. First, I'll introduce you to how MATLAB handles arrays and array indexing. Then, I'll take you through a flow chart of an example problem to visualize how an array can be updated during each loop pass. Finally, I'll walk you through the implementation of a for loop in MATLAB with array indexing and storage in an array. If you are unfamiliar with for loops, I'd recommend watching Parts 1 and 2 of the series (links below).
This is Part 3 of a 4 Part Series on for Loops.
Part 1 introduces the basic structure of a for loop and demonstrates a loop pass. Link to Part 1: • MATLAB for Engineers -...
Part 2 focuses on updating the value of a variable during each loop pass. Link to Part 2: • MATLAB for Engineers -...
Part 4 will introduce combining loops and logic by nesting the conditional statements if, elseif, and else inside of a loop. Link to Part 4: • MATLAB for Engineers -...
The background music in the intro and outro was written and produced by Michael J Calamas for the exclusive use of David Calamas.

[@angie25601]

Thank you for your video, I am using them to complement my practice with Matlab. Sometimes my book is difficult to follow but with your videos I can understand better the concepts and solve the exercises of my book.

[@kapisotieno2302]

Good lecture. I understand clearly the objective of this tutorial. I yearn for more. thanks

[@ranapratap4961]

glad u r back. I love ur videos bro.

[@user-tx5vx5if1r]

Really nice and helpful videos! Greetings from Greece!

[@SpartanProfessor]

Thanks for watching!

[@khadijahblagmon3077]

You are a life saver!

[@unstoppable5174]

U are my hero I swear !! Thankfully

[@krisatd4815]

very good lecture, please add more and more videos

[@ravindrakhakural6757]

Great Explanation, you are able to save my dream to be graduated

[@AdityaSingh-kw8bi]

great to see you again bro we will be rich soon :) loves your videos

[@ayush3334]

dude, thanks so much!!!!!!!!!!!!!!!!!

[@Antonio-ms3gb]

Catapimbas ! Muito bom !

[@ivanatoche6142]

Thank you a lot

[@SpartanProfessor]

You are welcome!

[@sam-kx3ty]

talented man haha!!

[@aklilug6597]

can u suggest on handling more than two indexes or variables in matlab. let's, for example, assume that Y is function of three variable, x,z,t and we want to have values of y as all variables change and store results at point of my interest. for example store values of y as t varies and x and z are kept at specific values.

[@hz2909]

How can we detect a sign change in a vector using for loop

[@sadiq114]

Very good way of teaching. Are you going to teach from the Matlab Book "Matlab for Engineers"? And if yes, then which edition? Further, are you going to continue these lectrures it or not? Regards

[@sadiq114]

@@SpartanProfessor thanks for your prompt reply. Can you email me that book? [e-mail]

[@eedeatlikkle3652]

Quick q, if you want to just use one value of y, say when i = 3 for some other calculation, how do you do that. Because if I write y in the conmand window it just gives me the latest y value (when i is 5)?? Would really appreciate a quick reply thanks

[@SpartanProfessor]

You can use an array index to reference the element you are interested in. In your case, y(3) would return the third element in y.

[@user-uy3hd2mv9t]

what if I wrote the following instead? for x=0:2:8; y=x^2 end is it the same? Thanks

[@ogechiogbonna368]

It's not the same the final output of your code will be a scalar i.e a 1 by 1 matrix But the final output of the code he has written will output an array of 1 x 5 matrix

[@stephenoni2019]

why'd you do it this way and not like the way you did in previous videos? why did you introduce "i" abruptly?

[@SpartanProfessor]

That's a good question. The index variable, i, is used to store values in a specific element in an array. For example, A(1) is the first element in A (where i = 1). Similarly, A(5) is the fifth element in A (where i = 5). So an array index can be used to tell MATLAB where to store a value. It can also be used to extract a value from an array from a specific location. I'm realizing this is difficult to explain in a comment... I may create a separate video for this topic. Thanks for commenting.

[@jacobhouston1655]

This y(i), the i character is giving me SUCH A HARD TIME watching your vidoes. Everything is smooth until that (i) comes up. Could yo uplease explain this whole (i) concept in a video by itlsef? Very frustrating. :(

[@jacobhouston1655]

I despise this (i). I don't understand it.

[@stephenoni2019]

I had trouble with this as well for many years now, and I think I just realized that i is a counter for all the numbers in the array, that is, it holds all the numbers you want to calculate a function for. So for y(i), you are calculating the function y at whatever value i is. That is the way I understand it at the moment. "i" can also be any letter or letters or whatever you want it to be, as long as you stay consistent during the course of your code.