How iterate inside a excel file and every 21 rows store values in a matrix?

I have a attached excel file, and I need to store values in col B and C for each 21 rows in different matrix. I am wondering how can I iterate through excel file and also have a loop to do this.

What I already have, it is pushing the first 21 rows for col B and C inside the ED_X and ED_Y, and the next 21 rows inside the ES_X and ES_Y. How can I do this through all the excel file?

The excel file is very large file. It does have 425272 rows. I just attached a sample of small file.

sheet1 = 'VolumeTracings';
xlRange1 = 'A2:H425272';
[XY,fileName] = xlsread('VolumeTracings.csv',sheet1,xlRange1);


Label_XY(:,1) = XY(:,1); %x1
Label_XY(:,2) = XY(:,2); %y1

ED_X =  Label_XY(1:21,1)
ED_Y =  Label_XY(1:21,2)

ES_X =  Label_XY(22:42,1)
ES_Y =  Label_XY(22:42,2)

Answer 1

[Takumi]

How about saving to a cell array？

sheet1 = 'VolumeTracings - Copy';
[XY,fileName] = xlsread('VolumeTracings - Copy.csv',sheet1);
% Label_XY(:,1) = XY(:,1); %x1
% Label_XY(:,2) = XY(:,2); %y1
Label_X = reshape(XY(:,1),21,[]);
Label_Y = reshape(XY(:,2),21,[]);

nmax = size(Label_X,2);
EX = cell(1,nmax); EY = EX;
for n=1:nmax
    EX{n} = Label_X(:,n);
    EY{n} = Label_Y(:,n);
end

[Neda]

Thank you for the snippet. It works. I have one more question. How about if I want to append the 21 rows of column 3 to the end of column one when it has 21 rows.

Fo example now Label_X = reshape(XY(:,1),21,[]); has 21 rows, I need to append at the end of each coulm in this matrix the 21 rows from coulmn 3 (X2), and the same thing would be repeat for Label_Y (first 21 rows of Y2 will append to the Y1)

[Takumi]

sheet1 = 'VolumeTracings - Copy';
[XY,fileName] = xlsread('VolumeTracings - Copy.csv',sheet1);
X1 = reshape(XY(:,1),21,[]);
Y1 = reshape(XY(:,2),21,[]);
X2 = reshape(XY(:,3),21,[]);
Y2 = reshape(XY(:,4),21,[]);
nmax = size(X1,2);
EX = cell(1,nmax); EY = EX;
for n=1:nmax
    EX{n} = [X1(:,n);X2(:,n)];
    EY{n} = [Y1(:,n);Y2(:,n)];
end

[Neda]

Thanks a lot

Answer 2

[David Hill]

I don't understand your question completely, but, I would put them all in a single matrix.

XY=reshape(XY(1:42,1:2),21,[]);