E255: Least-Squares Fit to Parabola

Author(s): H. Grote	Library: MATHLIB
Submitter: M. Metcalf	Submitted: 01.05.77
Language: Fortran	Revised:

Given a vector of values Y measured at the points X, PARLSQ finds the best least-squares fit to the parabola .

Structure:

SUBROUTINE subprogram
User Entry Names: PARLSQ

Usage:

    CALL PARLSQ(X,Y,L,C,VAR)

X

(REAL) Vector of abscissae.

Y

(REAL) Vector of values corresponding to points X.

L

(INTEGER) Length of vectors X and Y.

C

(REAL) Array of dimension 3 in the calling program. On exit, it contains the coefficients .

VAR

(REAL) Residual sum of squares divided by .

Notes:

If , C and VAR are set to zero.

References:

1. D.H. Menzel, Fundamental Formulas of Physics, Dover Publ., New York (1960) 122