Why was my code working then error message appears?

ive been using this code to run perfectly, but all of a sudden I get an error in the plotting that i dont understand can anyone let me know what please?

files=dir('*.dat');

%%Preallocate some cells

x=cell(1,numel(files));

y=cell(1,numel(files));

u=cell(1,numel(files));

v=cell(1,numel(files));

for i=1:numel(files) filename=files(i).name;

delimiterIn= ' ';

headerlinesIn = 3;

A= importdata(filename,delimiterIn,headerlinesIn);
c = 214;%columns i
r = 134;%rows j
dt= 0.0005; pix_c= 0.2643e-3;% m/pix
%%Save results
x{i}=reshape(A.data(:,1),r,c)*pix_c; % m
y{i}=reshape(A.data(:,2),r,c)*pix_c; %m
u{i}=(((reshape(A.data(:,3),r,c))*pix_c)/dt); %m/s
v{i}=(((reshape(A.data(:,4),r,c))*pix_c)/dt); %m/s
end

%% Mean Velcity matrices

V = cat(3, v{:}); V_m=mean(V,3);

U = cat(3, u{:});

U_m=mean(U,3);

%% Mean Velocities plot

%%%% V-mean%%

[X,Y]=meshgrid(0:max(x{1}(:)),0:max(y{1}(:)));

Vq=griddata(x{1}(:),y{1}(:),V_m(:),X,Y);

f1=figure;

contourf(X,Y,Vq);

xlabel({'x(m)'})

ylabel({'y(m)'})

title('V-mean velcity profile')

hcb=colorbar;

title(hcb,'Velocity [m/s]')

%%%% U-mean%%

[X,Y]=meshgrid(0:2:max(x{1}(:)),0:2:max(y{1}(:)));

Uq=griddata(x{1}(:),y{1}(:),U_m(:),X,Y);

f2=figure;

contourf(X,Y,Uq)

xlabel({'x(m)'})

ylabel({'y(m)'})

title('U-mean velcity profile')

hcb=colorbar;

title(hcb,'Velocity [m/s]')

[Guillaume]

I get an error

Giving us the full text of the error would be the first requirement to getting an answer. Copy/paste everything in red.

[Ernest Adisi]

Error using contourf (line 57) Z must be at least a 2x2 matrix.

Error in PIV_Post_Process (line 45) contourf(X,Y,Vq);

>>

Answer 1

[Ashutosh Sharma]

First you have to put all the values of the data/variables(filename,delimiterIn,headerlinesIn) then run the code may be you can run the code after that.