for loop concatenation for datasets

I am working on a code that combines datasets of equal sizes.

I want to create a loop that concatenates the datasets horizontally. In the loop below ds_temp will be recurrring datasets (200x2) that will need to be combined to form the final dataset ds. Can you please help?

ds = ds_temp;

ds = horzcat(ds,ds);

end

[Sven]

Joe, the above code (first 2 lines) does not error. Can you clarify your actual problem? Is it that you're not sure of the syntax for making a loop?

[Joe]

Thanks Sven for your response. You are right the code does not error. I am not sure of the syntax for making a loop as I am still learning to code! Each dataset has two columns - date and prices. I am able to get data for each datasets but the loop is currently overwriting all dataset and keeps the last dataset. I meed to save the first dataset and add all recurring datasets to the original dataset. I can also use the join function instead of concatenation to add all new datasets. I am just not sure of the syntax!

Answer 1

[Sven]

Hi Joe,

The following loop:

1. makes some random data (20-by-2)
2. initialises a variable called allData to start as 20-by-2
3. concatenates that random data onto allData, 5 times.

randomData = rand(20,2);
allData = randomData;
for i = 1:5
    dataToAppend = randomData + i;
    allData = [allData dataToAppend];
    % allData = cat(2, allData, dataToAppend);
    % allData = horzcat(allData, dataToAppend);
end

Note the two lines commented out. They do the exact same thing, just with slightly different syntax.

The end result will be a 20-by-12 matrix, because allData started at 20-by-2, and had 2 columns added to it 5 times.

[Johanna]

Um, might be just me, but this way you are also adding the value of i to randomdata on each loop? Surely that's not desired...

Answer 2

[Yesid Goyes]

How do I automatically concatenate several pages of the same multidimensional array.?

if true

    % cc=cat(1,xyz(:,:,1),xyz(:,:,2),xyz(:,:,3),...,xyz(:,:,n));

end