search for: 26x26

...onse measured over different time points (several days). I have already been able to create a cor() matrix of all the drugs for all the patients on each day. However I have been asked to prepare a matrix of all days of all people for all drugs. So since there are 26 drugs, I am expected to form a 26x26 matrix for all this data. I am not even sure if this is possible. Can anyone point me in the right direction? PS: If I make individual matrix and combine them using cbind(), it is not a 26x26 sqaure matrix. Any help would be greatly appreciated. Thanks