Correlation Coefficient (Corrcoef)

Suppose I have a matrix A=[3,2;2,3]. If I want to find the correlation coefficients of A using Aij/(Aii*Ajj)^1/2, I get the matrix C=[1 0.666;0.666 1](This result is also true, if I use the matlab command cov2corr()). But if I use the matlab command corrcoef(), which is using the same formula to calculate the correlation coefficients, I get the result C=[1 -1;-1 1]. Why is the result different? Kindly guide me.

Answer 1

[the cyclist]

Aij/(Aii*Ajj)^1/2

is not the matrix of correlation coefficients of A.

Cij/(Cii*Cjj)^1/2

is the matrix of correlation coefficients of A, where C is the covariance matrix of A.

This is explained in the Description section of the documentation for corrcoef.