How Can I find the equal elements in a matrix then plot the relationship between rows and columns that have equal elements?

Dears

I have a huge matrix where rows represent the maximum capacity, columns represent the storage and the elements are the expected unavailability of energy, I want to find the equal elements in my matrix then for each of these elements I want to plot the relationship between the maximum capacity and storage, How can I do this using matlab?

Any help will be appreciated since I need to submit a project tomorrow and I'm stucked.

Thanks