Taking a few columns out of a big array and making a new smaller one

I have a data array with 24 columns and a 10k+ rows of data. I want to take 4 of the columns (column 2,4,8,and a constant value of "1900") and make a new array for calculations. How do I do this?

Answer 1

[Image Analyst]

Try this:

smallArray = bigArray(:, [2,4,8]); % Extract columns 2, 4, 8.

Actually, I'm not sure what the "and a constant value of "1900"" means for your array of 24 columns. If you want to tack on a column of all values of 1900, do this

smallArray = [smallArray, 1900*ones(size(smallArray, 1), 1)];

[Bennett Torrance]

Hey thanks! That worked perfectly.

[Bennett Torrance]

How would I make it so the 1900 column is the first column instead of the last one?

[Image Analyst]

Just put it in front:

smallArray = [1900*ones(size(smallArray, 1), 1), smallArray];