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Fix bug #581: remove useless piece of code is blueNorm

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This commit is contained in:
Gael Guennebaud 2013-04-09 09:23:40 +02:00
parent d97cd746ae
commit 8f44205671
1 changed files with 18 additions and 18 deletions
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36
Eigen/src/Core/StableNorm.h
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@ -13,6 +13,7 @@
namespace Eigen { namespace Eigen {
namespace internal { namespace internal {
template<typename ExpressionType, typename Scalar> template<typename ExpressionType, typename Scalar>
inline void stable_norm_kernel(const ExpressionType& bl, Scalar& ssq, Scalar& scale, Scalar& invScale) inline void stable_norm_kernel(const ExpressionType& bl, Scalar& ssq, Scalar& scale, Scalar& invScale)
{ {
@ -41,43 +42,41 @@ blueNorm_impl(const EigenBase<Derived>& _vec)
using std::sqrt; using std::sqrt;
using std::abs; using std::abs;
const Derived& vec(_vec.derived()); const Derived& vec(_vec.derived());
static Index nmax = -1; static bool initialized = false;
static RealScalar b1, b2, s1m, s2m, overfl, rbig, relerr; static RealScalar b1, b2, s1m, s2m, overfl, rbig, relerr;
if(nmax <= 0) if(!initialized)
{ {
int nbig, ibeta, it, iemin, iemax, iexp; int ibeta, it, iemin, iemax, iexp;
RealScalar abig, eps; RealScalar abig, eps;
// This program calculates the machine-dependent constants // This program calculates the machine-dependent constants
// bl, b2, slm, s2m, relerr overfl, nmax // bl, b2, slm, s2m, relerr overfl
// from the "basic" machine-dependent numbers // from the "basic" machine-dependent numbers
// nbig, ibeta, it, iemin, iemax, rbig. // nbig, ibeta, it, iemin, iemax, rbig.
// The following define the basic machine-dependent constants. // The following define the basic machine-dependent constants.
// For portability, the PORT subprograms "ilmaeh" and "rlmach" // For portability, the PORT subprograms "ilmaeh" and "rlmach"
// are used. For any specific computer, each of the assignment // are used. For any specific computer, each of the assignment
// statements can be replaced // statements can be replaced
nbig = (std::numeric_limits<Index>::max)(); // largest integer ibeta = std::numeric_limits<RealScalar>::radix; // base for floating-point numbers
ibeta = std::numeric_limits<RealScalar>::radix; // base for floating-point numbers it = std::numeric_limits<RealScalar>::digits; // number of base-beta digits in mantissa
it = std::numeric_limits<RealScalar>::digits; // number of base-beta digits in mantissa iemin = std::numeric_limits<RealScalar>::min_exponent; // minimum exponent
iemin = std::numeric_limits<RealScalar>::min_exponent; // minimum exponent iemax = std::numeric_limits<RealScalar>::max_exponent; // maximum exponent
iemax = std::numeric_limits<RealScalar>::max_exponent; // maximum exponent rbig = (std::numeric_limits<RealScalar>::max)(); // largest floating-point number
rbig = (std::numeric_limits<RealScalar>::max)(); // largest floating-point number
iexp = -((1-iemin)/2); iexp = -((1-iemin)/2);
b1 = RealScalar(pow(RealScalar(ibeta),RealScalar(iexp))); // lower boundary of midrange b1 = RealScalar(pow(RealScalar(ibeta),RealScalar(iexp))); // lower boundary of midrange
iexp = (iemax + 1 - it)/2; iexp = (iemax + 1 - it)/2;
b2 = RealScalar(pow(RealScalar(ibeta),RealScalar(iexp))); // upper boundary of midrange b2 = RealScalar(pow(RealScalar(ibeta),RealScalar(iexp))); // upper boundary of midrange
iexp = (2-iemin)/2; iexp = (2-iemin)/2;
s1m = RealScalar(pow(RealScalar(ibeta),RealScalar(iexp))); // scaling factor for lower range s1m = RealScalar(pow(RealScalar(ibeta),RealScalar(iexp))); // scaling factor for lower range
iexp = - ((iemax+it)/2); iexp = - ((iemax+it)/2);
s2m = RealScalar(pow(RealScalar(ibeta),RealScalar(iexp))); // scaling factor for upper range s2m = RealScalar(pow(RealScalar(ibeta),RealScalar(iexp))); // scaling factor for upper range
overfl = rbig*s2m; // overflow boundary for abig overfl = rbig*s2m; // overflow boundary for abig
eps = RealScalar(pow(double(ibeta), 1-it)); eps = RealScalar(pow(double(ibeta), 1-it));
relerr = sqrt(eps); // tolerance for neglecting asml relerr = sqrt(eps); // tolerance for neglecting asml
abig = RealScalar(1.0/eps - 1.0); abig = RealScalar(1.0/eps - 1.0);
if (RealScalar(nbig)>abig) nmax = int(abig); // largest safe n initialized = true;
else nmax = nbig;
} }
Index n = vec.size(); Index n = vec.size();
RealScalar ab2 = b2 / RealScalar(n); RealScalar ab2 = b2 / RealScalar(n);
@ -125,6 +124,7 @@ blueNorm_impl(const EigenBase<Derived>& _vec)
else else
return abig * sqrt(RealScalar(1) + internal::abs2(asml/abig)); return abig * sqrt(RealScalar(1) + internal::abs2(asml/abig));
} }
} // end namespace internal } // end namespace internal
/** \returns the \em l2 norm of \c *this avoiding underflow and overflow. /** \returns the \em l2 norm of \c *this avoiding underflow and overflow.