Sara - how did you try to execute the code? Based on the given link, the function requires a rule (so this is an integer from 1 to 255), an optional initial state, and an optional number of rows (iterations for the cellular automata). What is your [1 0 1 1 0 1 1] - a rule or an initial state?
For example, the command
wolfram(45)
creates an interesting image, as does some of the other examples included in the comments (from the rich vector).
If your vector is an initial state, then you would specify the rule (1-255) and supply the state vector
wolfram(45, [1 0 1 1 0 1 1], 50);
Note that since your initial state is narrow (only 7 columns) then the number of rows should be kept small too else the image will be difficult to view.
