I need some help please. I have two columns in a matrix B. B=[A, X]; X is a column vector that contains different daily observations. A is a column vector that contains the number of the month (for example for January it has "1" for february "2" etc till December where it has "12").
Column X has daily data for January, Feb till december. Thus Column A has numbers that change according to the month number. For instance, for january, Column A will have thirty one "1" corresponding to 31 days in january and twenty nine "2" corresponding to 29 days in February until the end of the year then i will start again with january with "1" and february with "2" etc till december .
What I would like to do is to do the gemetric mean of the values of X for similar values of A. Basically, it is like if Iam doing a geometric mean month by month untill the end of my data series. How can I do that please? I am stuck in this. ANy help is much appreciated. Best