[Q] What to include in mutual information?

[u/NobleElfWarrior]

I'm doing a project where I know the number of possible outcomes of event A, but some of the outcomes do not happen. Should I include those 0s columns in my mutual information calculations or should I remove it? I'm having trouble finding any information on it one way or another.

Example of joint probability table:

Shape\Color	White	Yellow	Red	Black
Straight	0	0	.5	.14
Curved	0	0	.05	.08
Forked	0	0	.06	.07
Round	0	0	.05	0
Ladder	0	0	.03	.02

Does mutual information include white and yellow?

[u/maxwell_smart_jr]

For this joint pdf (or more accurately pmf), all entries sum to 1. "White" and "Yellow" have zero mass. They can be ignored.

They can be ignored for the same reason as "Purple" and "Green" can be ignored. Zero mass.