how to store values in csv format?

I have 1x500 matrix with doubles. I want to save it in a CSV file format

matrix=[a,b,c,d ,data];

dlmwrite('matrix.csv',matrix,'-append',delimiter,',') %saving data

the data is getting saved in excel sheet from 2nd row .

is there any way to save data from first cell of excel sheet?

Answer 1

[Voss]

Maybe try it without the '-append' option (and ',' is the default delimiter, so you don't need to specify it [and 'delimiter' needed to be in quotes anyway]):

dlmwrite('matrix.csv',matrix)

Also note that the documentation for dlmwrite recommends using writematrix instead.

[ramya]

from loop i will always get 1x500 matrix values

and each row will be of 1x500 and i have to save each row data in a CSV file format without overlappingg each other's data..

[Voss]

I see. In that case either one of these approaches will work:

1. Write the first line without '-append' and then all remaining lines with '-append'
2. Accumulate all rows into a matrix and write it to file one time at the end (without '-append')

[ramya]

Sorry sir , but i am not able to understand...

[Voss]

Your code might look like this (Option 1 above):

% you have a 1x500 matrix with doubles, called matrix

dlmwrite('matrix.csv',matrix); % write it. this is the first row

for ii = 2:N_rows % for the remaining rows
    
    matrix = randn(1,500); % you get the next 1x500 row of numbers somehow
    
    dlmwrite('matrix.csv',matrix,'-append'); % write it, appending to what's already in the file
    
end

Or your code might look like this (Option 2 above):

% you have a 1x500 matrix with doubles, called matrix

% build another matrix that will contian all the rows, call it all_matrix
all_matrix = matrix; % at first, it only has the first row

for ii = 2:N_rows % for the remaining rows
    
    matrix = randn(1,500); % you get the next 1x500 row of numbers somehow
    
    all_matrix(end+1,:) = matrix; % and add the new row to the end of all_matrix
    
end

% now that all_matrix has all the rows, write it to file:
dlmwrite('matrix.csv',matrix);