What are the differences and similarities of Lady Macbeth between the movie by Roman Polanski and the play?

As with any film, the director must make a final decision
as to which human being will portray a fictional character.  Thus Polanski chose the
thin, pale, almost waiflike actress Francesca Annis to portray Lady Macbeth.  She has an
air of innocence, yet sex appeal as well, particularly in scenes where she is partially
clad.  The biggest differences between the characterization of Lady Macbeth in the play
and in the movie is at the beginning.  As the character weakens in the play, the both
portrayals come closer together.

The Lady Macbeth of
Shakespeare's play is presented as a seemingly tough woman, mentally and psychologically
at least, that can bully her husband (a battle hero) into doing her bidding, including
regicide.  She seems to be more critical and more manipulative in the film whereas Ms.
Annis plays the character as more whiny and childish.

As
the play progresses and Lady Macbeth descends in to madness, the differences become less
pronounced.