How do I create another column in a table which basically divides a T+1 / T number?

I have a table (let's say X) with various colums. The first column is based on date.

I thought I could just do this;

DataVTAQ.Ret = (DataVTAQ(1,6)./(DataVTAQ(2,6)))

So I create a new column (RET), which is nothing else but the % change between 2,6 and 1,6 (a lag of t-1) basically.

How would one go about that?

Answer 1

[KSSV]

x = rand(10,1) ; 
y = rand(10,1) ; 
T = table(x,y) 

T = 10×2 table
       x          y    
    _______    ________

    0.13482     0.74789
    0.40312     0.25586
    0.31269       0.604
    0.83958     0.52914
    0.31587     0.46031
    0.79854     0.25194
    0.81289    0.082865
    0.17218     0.69191
    0.54784     0.15748
    0.21236     0.57421

T.ratio = T.y./T.x 

T = 10×3 table
       x          y         ratio 
    _______    ________    _______

    0.13482     0.74789     5.5472
    0.40312     0.25586    0.63469
    0.31269       0.604     1.9317
    0.83958     0.52914    0.63024
    0.31587     0.46031     1.4573
    0.79854     0.25194     0.3155
    0.81289    0.082865    0.10194
    0.17218     0.69191     4.0186
    0.54784     0.15748    0.28746
    0.21236     0.57421     2.7039

[Andy Simmons]

Hi, thanks. What I meant, is there a way to get the ratio column, where you calculate the ratio vector showing the results of y2/y1, y3/y2, etc, meaning leaving the first figure in ratio as NAN?

[KSSV]

The samething is shown in example. To remove/ eliminate NaN's read about isnan.

[Andy Simmons]

What I meant was, rather than where ratio shows (3,2) = 0.63469

Id' my trying to get the figure; 0.342109, which is (Y2)./(Y1), so not

T.ratio = T.y./T.x

but T.ratio = T.y(2)./(T.y(1)