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for loop concatenation for datasets

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Joe
Joe 2012-2-25
评论： Johanna 2018-2-28
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
  2 个评论
Sven
Sven 2012-2-25
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
Joe 2012-3-3
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!

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Sven
Sven 2012-3-3
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.
  1 个评论
Johanna
Johanna 2018-2-28
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...

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Yesid Goyes
Yesid Goyes 2013-6-10
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

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