Gauss Elimination - Simple MATLAB CODE/ PROGRAMMING

In this Method You will able to understand the MATLAB Code for Gauss Elimination

[@Mayoran2]

This really helped, thank you so much

[@DipakChavan]

thanks

[@lordcrasty]

exactly 4 years later, thanks

[@mubinkhan2450]

Sir i think there are some problem to calculate the value of x matrix when you will try to calculate x(3 or more) it will not give correct answer. i found a correct answer applying this.......... for i = n:-1:1 t = b(i,:); for j = n:-1:i t = t-(A(i,j)*x(j,:)) end x(i,:) = t/A(i,i); end x

[@kerlypadilla4026]

can you explain that please?

[@uriel4829]

Thank you! Mine only printed the number. maybe this is because we are using Octave isntead of Matlab.

[@kunalshegokar125]

"for i=n-1:-1:1" sir couldn't understand this line. why did you use -1? by the way this was the most simplified code i have ever seen for gauss elimination. Thank you

[@DipakChavan]

in gauss elimination we find the variables from bottom to top...& in hat also we found the last variable (suppose z) at early...and then we found the remaining variables... so for x, y, z z is at 3rd position y is at 2nd & x is at 1st position so n = 3 and as z is find earliest after z, y(n-1) & then x(n-2) therefor we use n-1:-1:1( backward substitution)

[@BikiniMadScientist]

You saved me thank you so much

[@sirinesandid829]

hello thank you for the video but when i implemented this program it gaves me for the two first cordinates of x zero only the last coordinate is calcualted

[@DipakChavan]

sirine sandid give me ur problem

[@sirinesandid829]

when i tried your code posted here x = 0 0 3.1 always i have the fisrt and the second argument =0

[@sirinesandid829]

close all clc A=[12 -2 3; 1 10 -2; 3 1 15]; b=[18;16;52]; %solve linear system Ax=b % A is n by n matrix % x is an n by 1 matrix [n,~]= size(A); x= zeros(n,1); %initialize x %code for forward elimination to correct the matrix A to upper triangular %form for i =1: n-1 m=A(i+1:n,i)/A(i,i); A(i+1:n,:)=A(i+1:n,:)-m*A(i,:); b(i+1:n,:) = b(i+1:n,:)-m*b(i,:); end %code for back substitution to find unknowns x(n,:)= b(n,:)/A(n,n); for i= n-1:1:1 x(i,:) =(b(i,:)- A(i,i+1:n)*x(i+1:n,:))/A(i,i); end x %display all values

[@DipakChavan]

when I solve it the result is as below... x = 1.0748 2.1147 3.1107 >> x=inv(A)*b x = 1.0748 2.1147 3.1107

[@sirinesandid829]

thank you i didn't write x =inv(A)*b

[@rashedulislamseum7936]

Very Good Explanation. Thanks A lot, Mr.Dipak Chavan

[@angelodebritoalfeu4333]

3 years later... Thank you.

[@beoptimistic5853]

kzbin.info/www/bejne/joGmmHqKbqefqLM 💐

[@patan61]

easy and functional! all you need.. thanks

[@venkatramana7822]

Thank you so much this helped me a lot

[@vaddadisreevamsi947]

how to do it for rectangular matrix , can u help me ? Thanks in Advance.

[@beoptimistic5853]

kzbin.info/www/bejne/joGmmHqKbqefqLM 💐

[@mohammedabokhadeje87]

really helped me ,thanks

[@nehalranabhatt7127]

can you please explain logic of last the equation used to fine the values of x2 and x3

[@DipakChavan]

I already explain it in the video...u just listen it and u'll find ur answer...

[@Dzawlin88]

How to do it when b=Ax and x = [1,....1]T ?

[@beoptimistic5853]

kzbin.info/www/bejne/joGmmHqKbqefqLM 💐

[@dr.engineering201]

I need help to solve a matrix problem, is there a way I can contact you so I can send my problem to you, then could you email me the file.

[@DipakChavan]

Philip Hammond Hello... U can also share ur problem here itself....

[@dr.engineering201]

Dipak Chavan, substitute the values from the table and create four simulations equations and solve a1, a2, a3 and a4, using Gaussian elimination to solve the four unknown quantities. The data relationship is u=a1t+a2t^2+a3t^3+a4t^4 Data T/s. U/ms^-1 0.125 0.75 0.250 1.50 0.375 0.75 0.500 0.00 Could you solve this using Gaussian eleimination and show me step by stem how you got your answer, thank you

[@dr.engineering201]

Can you send me a copy of the file when complete on matlab

[@DipakChavan]

R u really the Philip Hammond?

[@dr.engineering201]

Yes I am Philips Hammond, I don’t know why that a problem. I am asking this question on the behalf of my sone, please can you help!

[@sundarganesh3903]

can it work for nxn matrix?

[@SeifKoretum]

it worked with 4x4 with me