It is good practice to avoid `i`

and `j`

variables to prevent confusion about them being variables or the imaginary unit.

Personally, however, I use `i`

and `j`

as variables quite often as the index of short loops. To avoid problems in my own code, I follow another good practice regarding `i`

and `j`

: *don’t* use them to denote imaginary numbers. In fact, MATLAB’s own documentation states:

For speed and improved robustness, you can replace complex

`i`

and`j`

by`1i`

.

So rather than avoiding two very commonly used variable names because of a potential conflict, I’m explicit about imaginary numbers. It also makes my code more clear. Anytime I see `1i`

, I know that it represents `sqrt(-1)`

because it could not possibly be a variable.