ND - you can try using uiimport to import the data from your text file into an appropriately named variable. When I tried this, using your sample data from above, I had to merge two of the cells to get -1. Once the data has been imported, you can then calculate the sum of the rows. For example, suppose the data is now in a variable as
data = [0 0
1 2
2 5
-1 -2];
You can determine the sum of each row as
rowSums = sum(data')';
