Isolines Art Illustration: The
Chakana, Inca Cross
Chakana or Inca Cross is a symbol of the
Inca mythology. The geometrical design is made with
basic shapes like rectangle, square, triangle and circle.
A contour line (also isoline, isopleth, or isarithm) of a function of two variables
is a curve along which the function has a constant value.
Isolines usually have a parallel trend.