macOS Plotting a stream function in matlab

How does one do this?

I am trying to plot

PSI = Acos(6x)-Uy where A=1 and U=1 over an x range of -2000-200 and y from -2000-2000


My code is this and it is giving me an error.


x = -2000:1:2000;
y = -2000:1:2000;
si = zeros(x,y);
for x = -2000:1:2000
for y = -2000:1:2000
si(x,y) = cos(6*x)-y;
end
end
plot(si)

Thanks for any help

SidBala said:

What is the error?

I am not sure what you are trying to do here. Are you trying to make a 3D graph of cos(6*x) - y over x = [-2000,2000] and y = [-2000,2000] ?

Click to expand...

This is my error

??? Attempted to access si(-2000,-2000); index must be a positive integer or logical.

Error in ==> si5 at 6
si(x,y) = cos(6*x)-y;

Click to expand...

Essentially, I want to plot the si function over many values of x's and y's that will result in somewhat parrallel plots so to speak.

Something that looks like this
http://upload.wikimedia.org/wikiped...le_mass_plot.png/650px-Particle_mass_plot.png