column to multiple row conversion

Question

TESFALEM ALDADA 2020-3-3

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https://ww2.mathworks.cn/matlabcentral/answers/508749-column-to-multiple-row-conversion

编辑： per isakson 2020-3-5

Hi,

I wanted to convert a column vector in to multiple rows. The target is i have column of 1 year precipitation data (365,1) and i wonted to convert this in to 12*31 (month by days) matrix including leap years.

Who can can help me with this?

With kind regards,

Tesfalem,

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David Hill 2020-3-3

The above is for a cell array. If you want a matrix you are going to have to pad the months that have less than 31 days with some value (zero maybe or nan). What are you trying to do? Why would a cell array not work?

TESFALEM ALDADA 2020-3-4

Okey lets consider I have 31 days for all months (teplacing it by nan), then how would look like the new method to convert it in to row for one year,and also how can i apply it for long years.

Thank you!

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Answer 1

per isakson 2020-3-4

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https://ww2.mathworks.cn/matlabcentral/answers/508749-column-to-multiple-row-conversion#answer_418355

编辑：per isakson 2020-3-5

在 MATLAB Online 中打开

Try

col = rand(366,1); % sample data
mat = col2mat( col, 2020 );

and

col = rand(365,1); % sample data
mat = col2mat( col );

where

function    mat = col2mat( col, year )
    
    narginchk(1,2)
    if nargin==1
        if numel(col)==365
            year = 2001;    % not a leap year  
        elseif numel(col)==366                          % Fixed error; replaced 365 by 366
            year = 2000;    % a leap year
        else
            error( 'Wrong length of col, %d.', numel(col) )
        end
    end
    
    mat = nan( 31, 12 );        % pad with NaNs
    len = eomday( year, 1:12 );
    
    ix1 = [ 1, cumsum(len(1:11))+1 ];   % first day of month
    ix2 = [ ix1(2:end)-1, sum(len) ];   % last day of month
    
    for jj = 1 : 12
        mat( 1:(ix2(jj)-ix1(jj)+1), jj ) = col(ix1(jj):ix2(jj)); 
    end
end