Need help on how to construct proper data structure using vector

Question

I have several data files need to be loaded to my application. The data file has only 2 columns: "mean" and "standard deviation". The data file is looking like following:
mean standard deviation
217.0 27.3
312.1 31.5
I used two vectors to store the mean data and standard deviation data.
Vector meanVec = new Vector();
Vector stdVec = new Vector();
the file is loaded once a time. so how to make a vector of vector to store the data like a matrix?
In another word, when multiple files need to be loaded, how can I keep track and store these data to display in two table (or files) which can display mean data from all the files and std from all files, like the following:
table1 or file1
mean1 mean2
217.0 282.3
table2 or file2
std1 std2
27.3 27.9
Any suggestion is greatly appreciated!

Answer 1

If your application doesn't require to keep track of which mean (or std.dev.) values come from which file, whatever you are doing is just fine.
Use ArraList in place of Vector, as Vector being part of older collection framework is avoided in newer programs (as far as I know).
While reading each file line by line in a loop, store the first value on each line in one list and the second value in the other. After reading all the files, you would have two lists containing the mean and std. dev. values.