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SUBROUTINE POLRT

PURPOSE
   COMPUTES THE REAL AND COMPLEX ROOTS OF A REAL POLYNOMIAL

USAGE
   CALL POLRT(XCOF,COF,M,ROOTR,ROOTI,IER)

DESCRIPTION OF PARAMETERS
   XCOF -VECTOR OF M+1 COEFFICIENTS OF THE POLYNOMIAL
	 ORDERED FROM SMALLEST TO LARGEST POWER
   COF	-WORKING VECTOR OF LENGTH M+1
   M	-ORDER OF POLYNOMIAL
   ROOTR-RESULTANT VECTOR OF LENGTH M CONTAINING REAL ROOTS
	 OF THE POLYNOMIAL
   ROOTI-RESULTANT VECTOR OF LENGTH M CONTAINING THE
	 CORRESPONDING IMAGINARY ROOTS OF THE POLYNOMIAL
   IER	-ERROR CODE WHERE
	 IER=0	NO ERROR
	 IER=1	M LESS THAN ONE
	 IER=2	M GREATER THAN 36
	 IER=3	UNABLE TO DETERMINE ROOT WITH 500 INTERATIONS
		ON 5 STARTING VALUES
	 IER=4	HIGH ORDER COEFFICIENT IS ZERO

REMARKS
   LIMITED TO 36TH ORDER POLYNOMIAL OR LESS.
   FLOATING POINT OVERFLOW MAY OCCUR FOR HIGH ORDER
   POLYNOMIALS BUT WILL NOT AFFECT THE ACCURACY OF THE RESULTS.

SUBROUTINES AND FUNCTION SUBPROGRAMS REQUIRED
   NONE

METHOD
   NEWTON-RAPHSON ITERATIVE TECHNIQUE.	THE FINAL ITERATIONS
   ON EACH ROOT ARE PERFORMED USING THE ORIGINAL POLYNOMIAL
   RATHER THAN THE REDUCED POLYNOMIAL TO AVOID ACCUMULATED
   ERRORS IN THE REDUCED POLYNOMIAL.