Horner's rule for polynomial evaluation: Difference between revisions
Horner's rule for polynomial evaluation (view source)
Revision as of 10:28, 11 December 2015
, 8 years ago→Fortran 77: Fortran disregards spaces, but humans cn read the
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Line 540:
INTEGER I,N
DOUBLE PRECISION A(N),X,Y,HORNER
Y = A(N)
DO I = N - 1,1,-1
Y = Y*X + A(I)
END DO
HORNER=Y
Line 552:
C COMPUTE POLYNOMIAL VALUE AND DERIVATIVE
C SEE "ROUNDOFF IN POLYNOMIAL EVALUATION", W. KAHAN, 1986
C POLY: A(1) + A(2)*X + ... + A(N)*X**(N-1)
C Y: VALUE, Z: DERIVATIVE
IMPLICIT NONE
INTEGER I,N
DOUBLE PRECISION A(N),X,Y,Z
Z = 0.0D0
Y = A(N)
DO 10 I = N - 1,1,-1
Z = Z*X + Y
10 Y = Y*X + A(I)
END</lang>
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