How to create a vector from a loop?

How could I save each iteration of the loop in a vector?

M=[-15.00 -5.00 5.00 15.00 19.93 0.1 4.86 -80.5 326.858 3092.000
-15.00 -5.00 15.00 25.00 23.61 0.0 7.33 32.0 96.830 3092.000
-15.00 -5.00 25.00 35.00 19.64 0.1 8.20 73.7 32.218 3092.000
-15.00 -5.00 35.00 45.00 18.43 2.1 7.43 -9.5 15.117 3092.000
-15.00 -5.00 45.00 55.00 13.72 4.9 7.16 125.9 6.429 3092.000
-15.00 -5.00 55.00 65.00 10.50 0.4 4.01 -82.8 3.076 3092.000
-15.00 -5.00 65.00 75.00 9.75 0.6 4.25 -18.5 1.904 3092.000
-15.00 -5.00 75.00 85.00 9.84 2.2 4.96 -70.1 1.345 3092.000
-15.00 -5.00 85.00 95.00 9.82 4.5 8.28 24.0 0.976 3092.000
-15.00 -5.00 95.00 105.00 11.09 3.5 -1.27 30.1 0.827 3092.000];

for i = 1:length(M)
v= (M(i,3))-((abs(M(i,2)))*i);
end

We should obtain a vector v like

v=[0
   5
   10
   15
   20
   25
   30
   35
   40
   45];

Answer 1

[Paolo]

Simply preallocate and then write to the column vector:

v = zeros(size(M,2),1);
for i = 1:size(M,2)
v(i,1)= (M(i,3))-((abs(M(i,2)))*i);
end