How to frormat Table to use Previous Values for Calculations

Does anyone know how to format a table to use the previous values of a column to calculate the a new value. For example, using a base code of

x = (0:1:9)'
y = (2.*x)
T = table (x, y)

where I would like to subtract the previous value of Y to calculate a new Y value of:

x = (0:1:9)'
y = (2.*x-y)
T = table (x, y)

Is only producing 0s for the new Y value, whereas the table that looks like this is the desired outcome. The initial values of Y (used to calculate the first Y value) is 0

x = (0:1:9)'
y = [0; 2; 2; 2; 2; 2; 2; 2; 2; 2]
T = table (x, y)

Answer 1

[Cris LaPierre]

I would use the table variable T

% original table
x = (0:9)';
y = (2*x);
T = table (x, y)

T = 10×2 table
    x    y 
    _    __

    0     0
    1     2
    2     4
    3     6
    4     8
    5    10
    6    12
    7    14
    8    16
    9    18

% New Y values
T.y=(2*T.x-T.y)

T = 10×2 table
    x    y
    _    _

    0    0
    1    0
    2    0
    3    0
    4    0
    5    0
    6    0
    7    0
    8    0
    9    0

The reason the new y values are all zero is because, in the original table, y is 2*x, so your new equation is really , which equals 0. You need a different equation to get the result you want.