vlt.image.inside_ellipse

  INSIDE_ELLIPSE - Return 1 when a point is inside of an ellipse

   Z = INSIDE_ELLIPSE(X, Y, X_CTR, Y_CTR, A, B, THETA)

   Returns 1 when the point X(i), Y(i) is inside the ellipse
   with center at X_CTR, Y_CTR, with X axis vertex A and
   Y axis vertex B, rotated at an angle THETA (in radians), where
   angles increase according to a compass reference

   See also: INPOLYGON, CARTESIAN2COMPASS, COMPASS2CARTESIAN, DEG2RAD