How can I explain the correlation between variables in the bar 3D?

I have different figures that I plot them from MATLAB with different parameters. I know that if the x values increase and y values increase, thats mean strong liner correlation between variables and it is clear from scatter plot. on the other hand, if I have bar 3D ( which involve x,y and z axises ), how can I explain the correlation? Thanks advance.

Answer 1

[Star Strider]

The correlation remains however you represent your data.

[bader almulhim]

for this figure, if the values of x increase, y values decrease? It is confusing.

[Star Strider]

Only the sign of the correlation is dependent on the direction of the change in y with respect to x. The value remains the same.

For instance:

x = linspace(1, 20, 25);
y1 = 1./x + 0.1*randn(size(x));             % Decreasing
y2 = fliplr(y1);                            % Increasing

r1 = corrcoef(x,y1)
r2 = corrcoef(x,y2)

figure(1)
plot(x, y1,    x, y2)
grid

r1 =
     1.0000e+000  -628.8384e-003
  -628.8384e-003     1.0000e+000
r2 =
     1.0000e+000   628.8384e-003
   628.8384e-003     1.0000e+000

So if y increases with increasing x, the correlation will be positive, if y decreases with increasing x, the correlation will be negative.

[bader almulhim]

Thanks. It is clear now.

[Star Strider]

My pleasure.