subtract and save in a file and then plot

I have a file with 5 columns and 100 rows i.e like:

1 2 3 4 5

6 7 8 9 0

2 5 4 9 2

7 4 9 3 5 .....

and so on. I have to subtract 10 from 5th column then add the resultant to 4rth column and then make a new file with 1st, 2nd, 3rd & 4rth column of above file as it is plus a new column containing result of above i.e the one with the values we got after adding resultant to 4rth column.

plz help me with the program

Answer 1

[dpb]

b=[a(:,1:4) a(:,5)-10+a(:,4)];

Read the "Getting Started" section in the Matlab documentation and work thru the examples on array handling w/ colon and so on to get a feel for the syntax.