Find monthly mean from daily data of same year using find function

Hi I have a spreadsheet contains 1 year data and I want to find monthly mean column1 contains dd-mmm-yyyy And column2 contains data

Answer 1

[KSSV]

REad about datevec. This will give you years, months and days. Using the months and your data you can find mean. Let thedates be your dates and A be your data.

[y,m,d] = datevec(thedates) ; 
iwant = zeros(12,1) ;
for i = 1:12
    iwant(i) = mean(A(m==i)) ; 
end

[Guillaume]

Since datetime was introduced in R2014b, there's really no reason to use outdated functions such as datevec.

Matlab has plenty of aggregration functions that make this sort of task dead easy. Note that your code will not work properly if there is more than one year in the data (assuming the monthly mean per year is wanted).

[KSSV]

Guillaume Yes I agree, we have lot of functions to utilize. Most of the users here are beginners and they ask question to learn (I assume,:)). I gave a basic answer to show them how this can be done, so that they can learn.

[Guillaume]

Well, I'm sorry to say but you're teaching beginners bad practices. As I said, your code will not work properly if the there is more than one year in the data.

And your code cannot be easily changed to aggregate the data per quarter or per week. Using retime, it's as trivial as specifying 'quarterly' or 'weekly' instead of 'monthly'. And the intent is of course much clearer.

[KSSV]

As the use said..the data is of one year.....quickly I gave that....

Answer 2

[Guillaume]

The easiest way:

data = readtimetable('C:\somewhere\somefile.xlsx');  %may need some adjustement depending on the actual format of the line
monthlydata = retime(data, 'monthly', 'mean');

Done!