We have
seen that an important property of analytic functions is
that they are conformal transformations everywhere they
are defined, except where the derivative vanishes. More
precisely, if two curves intersect at a point and their
tangents make a certain angle there, then the angle
between the images curves under any analytic function
(with non-vanishing derivative) will be the same in both
magnitude and sense. A consequence of conformality,
namely the preservation of orthogonality of intersecting
coordinate lines, is visible in the following animation
where we use the power function
,
which is conformal everywhere except at the origin. Here
we apply the map to a square grid in the first quadrant,
with the power a varying from 1 to 3.9. Notice how all
the right angle intersections remain right angles
throughout the transformation, except the angle at the
origin, where the power maps are not conformal: