Finding the delta (subtraction) of two cells in an existing matrix

Hi,

I have a matrix with 10^7 rows and 17 columns.

Column number 17 is the time and I want to add another column, 18, that will have the delta of these time steps..

for example:

1

5

15

will yield

4

10

I get do loops cause there are 10^7 million rows.. it would take ages. Any ideas? Perhaps a boolian expression would do the trick? Thanks!!!

Answer 1

[Star Strider]

Use the diff (link) function, and add a ‘0’ to the output, so the row lengths will be the same:

time = [ 1
         5
        15]

dtime = [0; diff(time)]

producing:

time =
     1
     5
    15

dtime =
     0
     4
    10

[itzhak mal]

thank you!

[Star Strider]

As always, my pleasure!