2d Unsteady state heat conduction equation using Gauss-seidel method

I Wrote the code for 2d unsteady state using jacobi method. Please check it is correct or not. close all

clear all

clc

%Solving the Unsteady state 2D heat conduction by Gauss Seidel Method(IMPLICIT SCHEME)

%Input Parameters

%Number of grid points

nx = 10;

ny = nx;

nt = 1400;

x = linspace(0,1,nx);

y = linspace(0,1,ny);

dx = x(2) - x(1);

dy = dx;

%Absolute error criteria > tolerance

error = 9e9;

tolerance = 1e-4;

dt = 1e-3;

%Defining Boundary conditions

T_L = 400;

T_T = 600;

T_R = 800;

T_B = 900;

T = 300*ones(nx,ny);

T(2:ny - 1, 1) = T_L;

T(2:ny - 1, nx) = T_R;

T(1, 2:nx - 1) = T_T;

T(ny, 2:nx - 1) = T_B;

%Calculating Average temperature at corners

T(1,1) = (T_T + T_L)/2;

T(nx,ny) = (T_R + T_B)/2;

T(1,ny) = (T_T + T_R)/2;

T(nx,1) = (T_L + T_B)/2;

%Assigning orginal values to T

T_old = T;

T_intial = T;

%Calculation of 2D steady heat conduction EQUATION by Gauss-seidel method

A= 1.1*(dt/(dx^2));

Gauss_Seidel_iteration = 1;

for k = 1:nt

    error = 9e9;

    while(error > tolerance)

        for i = 2:nx - 1

            for j = 2:ny - 1

                T(i,j)= T_intial(i,j).*(1-4*A) +  A *(T(i-1,j)+ T_old(i+1,j)+T(i,j+1)+T_old(i,j-1));

            end

        end

        error = max(max(abs(T_old - T)));

        T_old = T;

        Gauss_Seidel_iteration = Gauss_Seidel_iteration + 1;

    end

    T_intial = T;

    %Plotting

    figure(1)

    contourf(x,y,T)

    clabel(contourf(x,y,T))

    colorbar

    colormap(jet)

    set(gca, 'ydir', 'reverse')

    xlabel('X-Axis')

    ylabel('Y-Axis')

    title(sprintf('No. of Unsteady Gauss-Seidel Iterations(IMPLICIT) = %d', Gauss_Seidel_iteration));

    pause(0.03)

end