What to do when standard deviation is 0?

Hello everyone, I am trying to calculate the standard deviation of all columns in a dataset. And since some of the observations are identical, the standard deviation is equal to 0. But I am using that results in a multiplication afterwards. That's why I am getting zeros, infinites or NaNs. How can I avoid that?

[Christian Dieterich]

Maybe this will help you.

https://de.mathworks.com/matlabcentral/answers/44360-standard-deviation-ignoring-0s-in-matrix

[John D'Errico]

What to do? You can decide to accept that some of these standard deviations are zero, and thus further computations on them will be meaningless. That might mean you need to do something more intelligent afterwards, that handles zeros somehow "properly". But what is up to you, since we are given no clue as to what you are doing.

Or, you can get better data.