# 3d plot in matlab

1. Feb 17, 2009

### cpeng

i want to plot these equations in 3d

Eq 1= 5x^2 - 2y^2 + 4x+ 4y -4 +2xy
Eq 2 =x^2 +3x +2y +xy +5
eq 3 = -7x2 +3x -6y +5xy +2

i tried plot3 with 3 matix of x,y,z but i am not satisfied with the result.
plz if any one know how to plot these equations.let me know

2. Feb 17, 2009

### Topher925

What kind of plot are you trying to make? I'm going to assume a surface plot since you didn't specify. Here is an example using the "surf" command.

x = 1:1:100;
y = 1:1:100;
[X,Y] = meshgrid(x,y);
Z = X.^2.*Y.^3;
surf(X,Y,Z)

3. Feb 18, 2009

### cpeng

wel these 3 equations will represent 3 coordianted of plot(x,y,z)
combine plot of these equation. i have tried
ezsurf('-5*x.^2 - 2*y.^2 + 2*(x.*y) + 4*y + 4*x -4' ,'x.^2 +3*x +2*y +x*y +5 ','-7*x.^2 +3*x -6*y +5*(x.*y) +2 ');
thats work

4. Jun 26, 2009

### pkmalik

Hi, I have 3 vectors of the same dimensions and want to plot a graph in 3D as surface or volume. I tried but I couldn't. Any body knows?
Vectors arr:
A=[2 5 15 25 30]
B=[0.1 0.2 0.5 0.9 1.0]
C=[1870 1890 1920 2000 2050]

thanks,
PK

5. Mar 3, 2011

### pashasrp67

for this one u can use this,

also mention the x and y values, ie starting and ending as x=1:10; y=1:10;

surf(x,y,Eq 1);
surf(x,y,Eq 2);
surf(x,y,Eq 3);

6. Mar 3, 2011

### pashasrp67

so u can try with this

7. Mar 3, 2011

### pashasrp67

u can use plot3 function

as

plot3(A,B,C);