close all 
clear all 
clc

figure(1)
x=linspace(-3*pi,3*pi,200);
y=linspace(-2,2,200);
subplot(3,3,[1,3])
[X,Y]=meshgrid(x,y);
Z=X.*cos(X).*abs(sin(Y).^2);
N_mat(:,1)=y
mesh(X,Y,Z)
xlabel('x')
ylabel('y')
zlabel('z')
colorbar

subplot(3,3,[4,7])
X=-2*pi;
Z=X.*cos(X).*abs(sin(y).^2);
N_mat(:,2)=Z;
plot(y,Z,'k')
xlabel('x')
ylabel('Z')
legend('z=f(x,y) for x=-2*pi')


subplot(3,3,[5,8])
X=pi/2;
Z=X.*cos(X).*abs(sin(y).^2);
N_mat(:,3)=Z;
plot(y,Z,'b')
xlabel('x')
ylabel('Z')
legend('z=f(x,y) for x=pi/2') 


subplot(3,3,[6,9])
X=2*pi;
Z=X.*cos(X).*abs(sin(y).^2);
N_mat(:,2)=Z;
plot(y,Z,'r')
xlabel('x')
ylabel('Z')
legend('z=f(x,y) for x=2*pi')

save N_mat
xlswrite('Matrix_A.xlsx','Next Columns','Sheet','A4:A1000')

clear all

load N_mat
figure(2)
subplot(1,3,1)
plot(N_mat(:,1),N_mat(:,1),'k')
legend('Z from N_mat, for X=-2*pi')

subplot(1,3,2)
plot(N_mat(:,1),N_mat(:,2),'b')
legend('Z from N_mat, for X=pi/2')

subplot(1,3,3)
plot(N_mat(:,1),N_mat(:,3),'r')
legend('Z from N_mat, for X=2*pi')