Monthly averages for each year using daily data in datenum form

Hi, I have matrix A (4000x2), the first column is daily data in datenum form. For example I have 734459, which using datestr brings 17-Nov-2010.

I did not see a post that answers this explicitly so I ask. How can I generate an array with monthly averages for each year of values of the second column? Thanks

Answer 1

[Guillaume]

See for example the answers to this question (for which the author unfortunately deleted away the original question, but it's essentially the same as yours).

Basically, use unique, or histc to bin your dates by year and month and find the indice of the bin each row lands in. Use accumarray with these indices to get the mean of column 2.

[Dave]

It is hard to follow the answers when you don't have the question but I sorted it out. Thanks

[Guillaume]

This answer is also similar (and the question is still there!)