FreeFOAM The Cross-Platform CFD Toolkit
polynomial.C
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5  \\ / A nd | Copyright (C) 2008-2010 OpenCFD Ltd.
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25 
26 #include "polynomial.H"
27 
28 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
29 
30 namespace Foam
31 {
32  defineTypeNameAndDebug(polynomial, 0);
33 }
34 
35 // * * * * * * * * * * * * * * * * Constructors * * * * * * * * * * * * * * //
36 
38 :
39  DataEntry<scalar>(entryName),
40  coeffs_(is)
41 {
42  if (!coeffs_.size())
43  {
44  FatalErrorIn("Foam::polynomial::polynomial(const word&, Istream&)")
45  << "polynomial coefficients for entry " << this->name_
46  << " is invalid (empty)" << nl << exit(FatalError);
47  }
48 }
49 
50 
52 :
53  DataEntry<scalar>(poly),
54  coeffs_(poly.coeffs_)
55 {}
56 
57 
58 // * * * * * * * * * * * * * * * * Destructor * * * * * * * * * * * * * * * //
59 
61 {}
62 
63 
64 // * * * * * * * * * * * * * * * Member Functions * * * * * * * * * * * * * //
65 
66 Foam::scalar Foam::polynomial::value(const scalar x) const
67 {
68  scalar y = 0.0;
69  forAll(coeffs_, i)
70  {
71  y += coeffs_[i].first()*pow(x, coeffs_[i].second());
72  }
73 
74  return y;
75 }
76 
77 
78 Foam::scalar Foam::polynomial::integrate(const scalar x1, const scalar x2) const
79 {
80  scalar intx = 0.0;
81 
82  forAll(coeffs_, i)
83  {
84  intx +=
85  coeffs_[i].first()/(coeffs_[i].second() + 1)
86  *(
87  pow(x2, coeffs_[i].second() + 1)
88  - pow(x1, coeffs_[i].second() + 1)
89  );
90  }
91 
92  return intx;
93 }
94 
95 
96 // ************************ vim: set sw=4 sts=4 et: ************************ //