behaviour of partialcorri: clarification needed

Dear everyone,

I have troubles understanding the behaviour of partiacorri function. More specifically, in the following example, I would have expected the variable rho2 to be equal to the second row of the matrix rho, but it is not the case.

load carsmall;
rng('default');  % For reproducibility
Headwind = (10:-0.2:-9.8)' + 5*randn(100,1);
y = [MPG,Acceleration];
x = [Displacement,Horsepower,Weight];
z = Headwind;

[rho,pval] = partialcorri(y,x,z,'Rows','complete')
[rho1,pval1] = partialcorri(y(:,1),x,z,'Rows','complete')
[rho2,pval2] = partialcorri(y(:,2),x,z,'Rows','complete')

which returns:

rho =

    0.0572   -0.1055   -0.5736
   -0.3845   -0.3966    0.4674

rho1 =

    0.0572   -0.1055   -0.5736

rho2 =

   -0.4024   -0.3699    0.4567

What am I missing here?

Thanks