how to graph vector fields containing scalar

I'm trying to graph some vector fields .

F(x,y,z)-<1,2,z>

F(x,y)=<0.3, -0,4)

my code is look like this

>> [x,y,z]=meshgrid(-2:2,-2:2,-2:2);

>> u=1;

>> v=2;

>> s=z;

>> quiver(x,y,z,u,v,s)

Second one is similar.

>> [x,y,]=meshgrid(-2:2,-2:2);

>> u=0.3;

>> v=-0.4;

>> quiver(x,y, u,v )

I tried to use ones(size(v)) function but it doens't work.

Any help would be helpful. Thank you

Answer 1

[Monisha Nalluru]

quiver used to for vector plot

The input arguments X,Y,U,V all should be of same size

In the above problem u,v should be same size of x,y

As an example

[x,y,]=meshgrid(-2:2,-2:2);
u=ones(size(x));
v=ones(size(x)) * 2;
quiver(x,y,u,v)

And inorder to increase the arrow length use scale argument

quiver(x,y,u,v,2) % scale the arrow length to 2 units

[VBBV]

@수정 이 In first case, it is a 3D plot , so you require quiver3 plot instead of 2D quiver function

[x,y,z]=meshgrid(-2:2,-2:2,-2:2);
u=ones(size(x));
v=ones(size(x)) * 2;
w = z;
s = 'r';  % color 
quiver3(x,y,z,u,v,w,s)