Matrix transformations

• (0 -1 1 0) = anticlockwise rotation of pi/2 around origin
• (0 1 -1 0) = clockwise rotation of pi/2 around origin
• (-1 0 0 1) = reflection in the y axis
• (1 0 0 -1) = Reflection in x axis
• (0 1 1 0) = reflection in the line y = x
• (-1 0 0 -1) = enlargement of SF -1 about the origin
• (2 0 0 1) = stretch by SF 2 in x direction
• (1 0 0 2) = enlargement by SF 2 in y direction
• (1 0 2 1) = shear with the y axis invariant and (1,1) moving to (1,3)
• (1 2 0 1) = shear with x axis invariant and (1,1) moving to (3,1)