Having trouble with quiver3() Sizing issues

The error shows:

if true
 clear all
nx=100;                              %Number of steps in space(x)
ny=100;                               %Number of steps in space(y)
nz=70;
tf=60;                               %Final time
dt=1e-2;                             %Width of time step
nt=ceil(tf/dt);                      %Number of time steps
dt=tf/nt;                            %Corrected time step
H=.2;                                %Height of the container
L=.82;                               %Length of the container
W=.5;
dx=L/(nx-1);                         %Width of space step(x)
dy=H/(ny-1);                         %Width of space step(y)
dz=W/(nz-1);
x=0:dx:L;                            %Range of x(0,2) and specifying grid points
y=0:dy:H;                            %Range of y(0,5) and specifying grid points
z=0:dz:W;
TN=25;                               %Top wall temperature
TS=70;                               %Bottom wall temperature
u=zeros(nx+1,ny);                    %Preallocating u
v=zeros(nx,ny+1);                    %Preallocating v
w=zeros(nx,nz+1);
p=zeros(nx,ny);                      %Preallocating p
S=zeros(nx,ny);                      %Preallocating S
uplot=zeros(nx,ny);                  %Preallocating uplot
vplot=zeros(nx,ny);                  %Preallocating vplot
To=min(TS,TN);                       %Initial temperature
T=To*ones(nx,ny);                    %Preallocating T (Initial conditions)
Re=1e2;                              %Reynolds number
Pr=7;                                %Prandtl number
Pe=Re*Pr;                            %Peclet number
Ra=1e2;                              %Rayleigh number
Gr=Ra/Pr;                            %Grashoff number
Tstar=T; 
ustar=u; uhalf=u; uconv=u;
vstar=v; vhalf=v; vconv=v;
TnE=0;   TnW=0;
UN=0;    VN=0;      
US=0;    VS=0;
UE=0;    VW=0;                  
UW=0;    VE=0;
for it=0:nt
  uplot(1:nx,1:ny)=0.5*(u(1:nx,1:ny)+u(2:nx+1,1:ny));
  vplot(1:nx,1:ny)=0.5*(v(1:nx,1:ny)+v(1:nx,2:ny+1));
  wplot(1:nx,1:nz)=0.5*(w(1:nx,1:nz)+w(1:nx,2:nz+1));
  if(rem(it,30)==0)        
      quiver3(x,y,z,uplot',vplot',wplot',5,'k');
      axis equal
      axis([0 L 0 H])
      hold on
      pcolor(x,y,z,T');
      colormap(jet)
      colorbar
      shading interp
      axis equal
      axis([0 L 0 H])
      title({['Rayleigh-Benard Convection with Pe = ',num2str(Pe),' and Gr = ',num2str(Gr)];['time(\itt) = ',num2str(dt*it)]})
      xlabel('Spatial co-ordinate (x) \rightarrow')
      ylabel('Spatial co-ordinate (y) \rightarrow')
      zlabel('Spatial co-ordinate (z) \rightarrow')
      drawnow;
      hold off
  end

Error using quiver3 (line 57) Z and U must be the same size.

Error in Benard_plot (line 47) quiver3(x,y,z,uplot',vplot',wplot',5,'k');

Answer 1

[Star Strider]

I’m not sure what you’re doing in your code, but according to the documentation for quiver3:

• quiver3(x,y,z,u,v,w) plots vectors with directions determined by components (u,v,w) at points determined by (x,y,z) . The matrices x,y,z,u,v,w must all be the same size and contain the corresponding position and vector components.

Your x, y, z are vectors, and uplot, vplot, wplot are (appropriately) matrices.

Answer 2

[Chad Greene]

From the documentation for quiver3, "The matrices X,Y,Z,U,V,W must all be the same size..." In your code, x and y are 1x100, z is 1x70, uplot and vplot are 100x100, and wplot is 100x70. The quiver3 function wants vector components u,v, and w for each point given by x, y, and z.

[Chad Greene]

On a side note, I'd make a habit of declaring more colors in your colormap for a smoother gradient in your colorbar. For example, colormap(jet(256)).