Join the curves and make them into one (overlap)

alpha=0.008;
gamma=3.3;
g=9.80665; 
delta_1=0.07; % if f<=fp
delta_2=0.09; % if f>fp
Tp=[2 8 16];   
fp_vector=1./Tp;  
i_freq=1:69;
f1=0.03093;  
c=1.1;
for i = 1:length(i_freq)
fi=f1.*c.^(i_freq-1);
end
 
f_vector=fi;    

nrows = length(f_vector); 
ncols = length(fp_vector);
E = ones(nrows,ncols);
fc = 0.4054;  


for i = 1:nrows         
    for j = 1:ncols      
        
        f = f_vector(i);
        fp = fp_vector(j);
        
        if f<fc 
            if f<=fp
            E(i,j) = (alpha*(g^2)*((2*pi)^(-4))*(f^(-5)))*exp((-5/4)*((f/fp)^(-4)))*gamma*exp((-1/2)*((f-fp)/(delta_1*fp))^2);
            else
            E(i,j) = (alpha*(g^2)*((2*pi)^(-4))*(f^(-5)))*exp((-5/4)*((f/fp)^(-4)))*gamma*exp((-1/2)*((f-fp)/(delta_2*fp))^2);
            end
        else
           if f<=fp
            E(i,j) = (fc/f)^5*(alpha*(g^2)*((2*pi)^(-4))*(f^(-5)))*exp((-5/4)*((f/fp)^(-4)))*gamma*exp((-1/2)*((f-fp)/(delta_1*fp))^2);
           else
            E(i,j) = (fc/f)^5*(alpha*(g^2)*((2*pi)^(-4))*(f^(-5)))*exp((-5/4)*((f/fp)^(-4)))*gamma*exp((-1/2)*((f-fp)/(delta_2*fp))^2);
           end
       end
        end
    end

E;

%%%  Dir(teta)

i_teta=1:36;
teta_i=10.*i_teta;
teta_i_cos=cos(2*teta_i);

for i = 1:length(teta_i_cos)
 if teta_i_cos>0
    dir_teta=0;
else
    dir_teta= (2/pi())*(1/2)*(1+teta_i_cos);%cos^2(x) = (1+cos2x)/2
end 
end

dir_teta;

f_teta=teta_i;

%%% T=2s
T2=E(:,1);

for i = 1:length(T2) 
   for j = length(dir_teta)
    
    Ef_teta_T2 = T2*dir_teta;
   end
end

Ef_teta_T2;



%%% T=8s
T8=E(:,2);

for i = 1:length(T8) 
   for j = length(dir_teta)
    
    Ef_teta_T8 = T8*dir_teta;
   end
end

Ef_teta_T8;



%%% T=16s
T16=E(:,3);

for i = 1:length(T16) 
   for j = length(dir_teta)
    
    Ef_teta_T16 = T16*dir_teta;
   end
end

Ef_teta_T16;



surf(teta_i, f_vector, Ef_teta_T2);
title('T=2s');
xlabel('{\it\theta} [degree

]');
ylabel('{\itf} [Hz]');
zlabel('{\itE(f,\theta)}[m^2/Hz/degree]');

I wonder if I can join the curves and make one (overlap)? The code is above and the graphic that came out is below.

But I wanted the graphic to look like this:

Thank you for your help

Answer 1

[Star Strider]

It looks to me that it needs to be plotted in polar coordinates.

First, define:

i_freq=1:0.1:69;

and:

i_teta=1:0.1:36;

then after plotting the first figure add:

[Teta_im,F_vectorm] = meshgrid(teta_i, f_vector);

[X,Y,Z] = pol2cart(Teta_im, F_vectorm, Ef_teta_T2);

figure
surf(X, Y, Z, 'EdgeColor','none')
grid on
axis([-1.0  1.0    -1.0  1.0    zlim])

producing:

This is not exactly like the second image you posted, however it is close! I will let you add the axis labels and other information, and make any other necessary changes, since I have no idea what you are doing.

[Jacqueline Rigatto]

Thanks for the help, Star Strider

[Star Strider]

My pleasure!

If my Answer helped you solve your problem, please Accept it!

To only plot half of the surface, with the contour lines:

[Teta_im,F_vectorm] = meshgrid(teta_i, f_vector);

[X,Y,Z] = pol2cart(Teta_im, F_vectorm, Ef_teta_T2);
Lm = X > 0;
X(Lm) = NaN;
Y(Lm) = NaN;
z(Lm) = NaN;

figure
surf(X, Y, Z, 'EdgeColor','none')
hold on
contour3(X, Y, Z, 15, 'r')
hold off
grid on
axis([-1.0  1.0    -1.0  1.0    zlim])
view(145,35

producing:

.