Select only January and April months among 30 years monthly data (how to filter?)

Hey all,

I have a cell (1 x 92) which includes 92 tables . In each table I have a column named dates. I want to filter the whole table based on January and April. I wish if it is possible have the value of January and April as 2 column after all existing column in each table (cell array), for example:

Thank you so much

[Walter Roberson]

In the rows corresponding to February, what value should be entered into the January column? table objects have to have the same number of rows for each variable.

[BN]

I didn't know that it is impossible to have a table with different row numbers for variables.

So if you please tell me how I can have another cell (like CELL.mat) but with tables that have columns of January and April and corresponding rrr24, I would be so grateful.

Thank you.

[Walter Roberson]

date_month = month(CELL{1,1}.dates);
jan_mask = date_month == 1;
april_mask = date_month == 4;
jan_rrr24 = CELL{1,1}.rrr24(jan_mask);
april_rrr24 = CELL{1,1}.rrr24(april_mask);

and now store those somewhere.

[BN]

Thank you very much. I wrote a for loop in order to do this for all cell arrays. I would be grateful if you can look at the code; because I get an error:

for i=1:numel(CELL)
    date_month = month(CELL{1,i}.dates);
    jan_mask = date_month == 1;
    april_mask = date_month == 4;
    jan_rrr24 = CELL{1,i}.rrr24(jan_mask);
    april_rrr24 = CELL{1,i}.rrr24(april_mask);
    table(i)(jan_rrr24, april_rrr24)
    newCELL = {table(i)}
end

the error:

Error: ()-indexing must appear last in an index expression. 

[Walter Roberson]

jan_rrr24 and april_rrr24 are already the extracted rrr24 values for the respective months.

You cannot construct a table that contains both jan_rrr24 and april_rrr24 entries because there are a different number of days in January (31) than in April (30) so you will not have the same number of rows for the two.

nCELL = numel(CELL);
newCELL = cell(nCELL, 2);
for i=1:nCELL
    date_month = month(CELL{i}.dates);
    jan_mask = date_month == 1;
    april_mask = date_month == 4;
    jan_rrr24 = CELL{i}.rrr24(jan_mask);
    april_rrr24 = CELL{i}.rrr24(april_mask);
    newCELL{i,1} = jan_rrr24;
    newCELL{i,2} = april_rrr24;
end

[BN]

Thank you !