your data format is called dense, because it only saves the indices of the columns unequal 0. RapidMiner supports a dense format, but it slightly differs from yours. If you could bring your data in the following format, you can easily load it:
2:1 3:1 4:1
1:1 2:1 3:1
If you then use the operator SparseFormatExampleSource with the parameter format set to no_label and the parameter dimension set to the number of dimensions (the highest number occuring in your file) then it works.
I am starting with market basket, so I have been practicing with datasets available in the internet.
I have used the 'retail' data set available at
http://fimi.cs.helsinki.fi/data/retail.dat, which is in the dense format.
But since I will get my own data from a friend's shop, my question is:
What is the best format for a market basket analysis with RM?