How to convert daily data to monthly?

I have huge number of precipitation daily data in a column (say for 60 years) for 400 meteorological stations. Now I need to convert it to monthly. How can I do that? thanks.

[per isakson]

Months have 28, 29, 30 or 31 days, which makes it a bit tricky.

Do you have a table with

    date, value

rather than just a column?

Does the length of the months matter?

[Mohammad]

my data format is Year Month Day data

that is in 4 column. Length of month is always 30. Does it help for providing your answer? thanks.

Answer 1

[Andrei Bobrov]

one way

M - your data matrix with 4 columns < Year Month Day data > - double type

[a,~,c] = unique(M(:,1:2),'rows');
out = [a, accumarray(c,M(:,4),[],@mean)];

Answer 2

[Chad Greene]

downsample_ts can do this by

precip_monthlymean = downsample_ts(precip_daily,t_daily);

[ABDULLA RAHIL]

Hi Chad I tried to use this equation but i couldn't i have a daily data and want to have monthly data

[Chad Greene]

My mistake--

precip_monthlymean = downsample_ts(precip_daily,t_daily,'monthly','mean');

Answer 3

[Babak]

Every 30 data rows, I would average them out and save it in 1 row.This way, 30 days shrinks down to 1 data (a month). Or another way, you can simply delete 29 data rows and keep only one from every 30 data rows.

[Mohammad]

Thanks. But please provide answer through matlab function.

[Babak]

you need to write what your variables are and we would know which format they are... I mean what type they are for example, string? double, or cell? moreover they are all in a matrix or a cell or how you ahev sorted them..

Answer 4

[per isakson]

Given thirty days in every month try this

    daily_val = rand( 30*12, 1 );
    daily_val = reshape( daily_val, 30, [] );
    monthly_val = sum( daily_val, 1 );

here I assume that the first value in daily_val is the first value of a month. This is intended as a start.

Answer 5

[ABHILASH SINGH]

You can try this;

https://in.mathworks.com/matlabcentral/fileexchange/74497-daily-data-to-monthly-average-sum-in-matlab?s_tid=LandingPageTabfx