Creating a table from different sized vectors

I have a number of vectors (x1,y1,x2,y2, etc) with different lengts and I want to extract them to a .csv containing all these. Specifically,

• 1st column = x1 (289 rows)
• 2nd column = y1 (289 rows)
• 3rd column = x2 (300 rows)
• 4th column = y2 (300 rows)

I try to use the horzcat but it does not work due to different size. Any ideas or solutions?

[Stephen23]

Rather than storing these in numbered variables these vectors should really be stored in a cell array. Then the task becomes a trivial loop with indexing to allocate the vectors into a proallcoated array.

Numbered variables are invariably a bad idea:

http://www.mathworks.com/matlabcentral/answers/196952-how-to-create-new-variables-in-batches-with-strcat

Answer 1

[Renato Agurto]

Hi, you could try:

 A = nan(no_of_columns, longest_array); % or zeros or whatever you want to fill the unused spaces

and then (or for example in a for loop):

 A(1:length(x1),1) = x1;
 A(1:length(y1),2) = y1;
 ...

I hope this is what you want

[ju.shu]

hey,

what if I have two columns each one of them 2xn (like 2x4012, and 2x9877) fo instance the columns represent points coordinates, how can I save the 2 columns in a table??

Thanks.

Answer 2

[the cyclist]

Depends on what you want to appear in the "empty" spot. You could use NaN. Then

 M = [[x1; nan], [y1; nan], x2, y2]

and then export the matrix M.

Answer 3

[the cyclist]

One possibility is to store them in a cell array first, in which case empty will be empty.

M = cell(300,4);
M(1:299,1) = num2cell(x1);
M(1:299,2) = num2cell(y1);
M(:,3) = num2cell(x2);
M(:,4) = num2cell(y2);

Answer 4

[Image Analyst]

I'd just use fprintf() and write it out manually.