How can I plot a sphere in 3D?

I have to plot this equation to obtain a sphere

wave=I.*exp(j.*(((k.*x.*sin(TETA).*cos(PHI))))+((k.*y.*sin(TETA).*sin(PHI))))

but the comands mesh, surf, sphere not functioning me. I define the variables as following

puntos=200;

puntos_1=400;

teta=linspace(0,pi,puntos); %0 a 180°

phi=linspace(0,2*pi,puntos_1); %0 a 360°

[TETA,PHI]=meshgrid(teta,phi);

Could anyone help me, please?

[David Goodmanson]

Are you trying to show the values of a plane wave on the surface of a sphere as the plane wave passes through that sphere? Or perhaps something different from that?

[Pilar Jiménez]

I trying to show the values of a plane wave (that obtain with the equation that I named "wave" in the code) like a sphere. The idea is each iteration of the values of teta and phi represent a position of the wave and the result represent the radiation of an antenna in position x=1 and y=1, then my radiation is in full range of teta and phi that's the reason for the plot a sphere. I have defined these variables:

I hope you understand my idea.

Answer 1

[Luca Fenzi]

This code works fine:

% PARAMETERS Of the model
I=1
x=1
y=1
k=1;
j=1;
%%Grid 
puntos=200; puntos_1=400; 
teta=linspace(0,pi,puntos); %0 a 180°
phi=linspace(0,2*pi,puntos_1); %0 a 360°
[TETA,PHI]=meshgrid(teta,phi);
% Model 
wave=I.*exp(j.*(((k.*x.*sin(TETA).*cos(PHI))))+((k.*y.*sin(TETA).*sin(PHI))))
mesh(wave)

An other option should be instead of using teta,phi, you can use

    [X,Y,Z]=sphere(N)

This will permit you to obtain a three dimensional grid of (N+1)x(N+1) points, but then your model wave must be changed from polar coordinate to Cartesian coordinate.

[Pilar Jiménez]

Thanks Luca, The problem is that the j is an imaginary unit not a real number, for this I can't give the value of 1. And at the end of my code I must have a sphere with the absolute results of my equation wave that is on a matrix with different dimensions matrix. I have defined these variables:

I=1;       %establecida por usuario
freq=30000000;  %30 Mhz - no. de ondas/seg
c=300000000000; %m/seg
wlong=c/freq;  %m
k=2*pi/wlong;   %no. onda