Function:     ELLIPSE1

Purpose:      Routine which gives an initial estimate for an ellipse to N
              points in the array X,Y.

Category:     MATH

File:         ellipse1.c

Author:       K.G. Begeman

Use:          INTEGER ELLIPSE1( N ,         Input      INTEGER
                                X ,         Input      REAL ARRAY
                                Y ,         Input      REAL ARRAY
                                P )         Output     REAL ARRAY

              ELLIPSE1   Returns 0 when successfull, and 1 on error 
              N          Number of points in X and Y.
              X          Array with X-coordinates.
              Y          Array with Y-coordinates.
              P          Estimated ellipse parameters:
                         P(1) = radius
                         P(2) = inclination (0..90 degrees)
                         P(3) = X0 (centre)
                         P(4) = Y0 (centre)
                         P(5) = position angle of major axis
                                (0..180 degrees) w.r.t. Y axis.

Related Docs: ellipse2.dc2

Updates:      Jan 23, 1991: KGB Document created.