Matlab surface - Tech Support Forums

elmers · April 6th, 2005, 01:03 PM

In matlab how would I create a surface or a countuour map form a matrix 3x1000 where each row is a point in 3d.

I have tried

Code:

plot3(matrix(1,:),matrix(2,:),matrix(3,:),.)

But that just gives me a point type of graph.

How can I transform this structure into something that surf could use?

elmers · April 6th, 2005, 08:24 PM

Bump: Anyone???

Elburn · April 6th, 2005, 08:50 PM

Have you tried using

Code:

surface(x,y,z,c)

Where x,y,z are your matricies, and the c is your color? I haven't tested that because I don't have anything handy to make a surface... but that's just a quick thought.

On second thought, have you tried taking your one mega-matrix and seperating into the x,y,z components, and then try to use surf?

elmers · April 7th, 2005, 08:17 AM

Tried splitting it into three vectors. Gives me an

Code:

??? Error using ==> surface
Arguments that are not parameter/value pairs must be numeric.

Elburn · April 7th, 2005, 05:14 PM

I don't know how helpful this will be, but this is sort of a simplified surface plotting exercise that I learned for z=x^2

Code:

x=-1:.1:1; %x matrix
y=-1:.1:1; %y matrix
[xx,yy]=meshgrid(x,y);
zz=xx.ˆ2; 
mesh(xx,yy,zz);
title(’The graph of z=xˆ2’)
xlabel(’x-axis’)
ylabel(’y-axis’)
zlabel(’z-axis’)
axis tight

The error said you didn't have numeric values... what was your code to split them up?

elmers · April 7th, 2005, 10:40 PM

Found that one last night. Still doesnt help me much. If someone doesnt come forward with an brutal soution Ill have to code it in a script.

Problem is zz needs to be matrix (2d) and mine is vector (1d).

How do you select the first n elments of a vector ? Or elements from n to m?

elmers · April 7th, 2005, 10:43 PM

Ok so to get the n-th thru m- th element in a vector you do an

Code:

x = y(n:m)

More of a note to myself really

b4codes · May 8th, 2006, 12:01 AM

you can easily parameterize your equations

example like plot(x, f(x), g(x, f(x))

otherwise try kluid ( http://www.kluid.com ) its a very good matlab forum, hope you will find the answer of your problem there

b4 : ]

Quote:

Originally Posted by elmers

Ok so to get the n-th thru m- th element in a vector you do an

Code:

x = y(n:m)

More of a note to myself really

elmers · May 9th, 2006, 06:25 AM

A year later ?!??! Really????!??!!