Can I multiply a Vector with a Matrix?

Hi;

Sorry for my english. I've a big problem, I want multiply a vector by a matrix:

A part of my code is:

[...]
x = -5000:10.:5000;
y = -5000:10.:5000;

[X,Y]=meshgrid(x);

U=   []; %is an array <1x15000 double>
teta=[]; %is an array <1x15000 double>
%condizioni iniziali

if U <= 5500
    rho = 0.1;
else U> 5500;
    rho = 0.16;
end

u = ((DeltaH/Hsor)^rho).*U ; 
%velocità del vento corretta

h = Hsor+DeltaH-((vg*2.1./u));
%altezza considerando la sedimentazione in atmosfera

dd=((270-teta)*pi)/180;
%Modifica direzione vento

x11 = cos(dd);

x111 = x11*X;

[...]

I've a problem in the last operation ??? Error using ==> mtimes Inner matrix dimensions must agree.

 Error in ==> SCORMAT at 90
 x111 = x11*X;

[EDITED, Jan, code formatted]

[Azzi Abdelmalek]

what is

if U 5500 rho = 0.1; else U 5500; rho = 0.16; end

[Edoardo]

U is wind speed and rho is a variable that change when change U

Answer 1

[Sachin Ganjare]

Change x11*X to x11.*X

[Edoardo]

Matrix dimensions must agree.

Error in ==> SCORMAT at 90 x111 = x11.*X;