What parallels do you notice between the characterization of Robert Walton and Victor Frankenstein?

Both Robert Walton and Victor Frankenstein are ambitious and sensitive souls. Like Victor, Robert wants to make new discoveries, which is why he has embarked on a risky journey to the Arctic.
Walton and Frankenstein also come from similar privileged class backgrounds and have known the support of loving families. The lonely Walton, rescuing the sick and famished Victor, sees in him a kindred spirit. The two are intellectual equals and Walton writes to his sister that Victor could be a friend. He says he sees sometimes in Victor's face

. . . a beam of benevolence and sweetness that I never saw equalled.

Just as Victor did, locking himself away in a lonely tower and denying himself the normal creature comforts in his obsessive quest to create life from inanimate matter, so Walton has denied himself an ordinary life to pursue his ambitions. As he writes to his sister:

I voluntarily endured cold, famine, thirst, and want of sleep. . . . Twice I actually hired myself as an under-mate in a Greenland whaler, and acquitted myself to admiration. . . . And now, dear Margaret, do I not deserve to accomplish some great purpose? My life might have been passed in ease and luxury, but I preferred glory to every enticement that wealth placed in my path.

This sounds very much like the voice of the young Frankenstein. It is because Victor perceives that Walton is ambitious, just as he used to be, that Victor tells his sad tale. He wants to caution Walton to lead a more balanced life.