Not sure what you are trying to do with Adi. If you solve the mathematical formula:
Adi = ((Vd + 1)-(Vd - 1)/(2*(.1));
Adi = (Vd-Vd + 1+1)/(2*(.1));
Adi = (2)/(0.2);
Adi = 10;
So you'll get 10, no matter what.
Next, it is unclear what you mean by "convert all i = 1 to 0"? Because i is not defined.
I guess you mean convert all values in Vdi that is == 1 to 0.
You definitely did not do this correctly.
Now, you did good by finding those values in Vdi that is equal to 1:
The problem that you had is in the assignment. You shoudl brush up on Matlab's indexing. But a hint:
Will get you all the data in Vdi that is equal to 1.
By itself, it is not all that useful, because you know that the output of this will be all 1s. But think about what you can do with it to achieve the assignment operation that you want to do.