3dpcp/.svn/pristine/c6/c6614c772d402605e92b677b2a7e28eacd8e6408.svn-base
2012-09-16 14:33:11 +02:00

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//$$ solution.h // solve routines
#include "boolean.h"
#include "myexcept.h"
#ifdef use_namespace
namespace RBD_COMMON {
#endif
// Solve the equation f(x)=y for x where f is a monotone continuous
// function of x
// Essentially Brent s method
// You need to derive a class from R1_R1 and override "operator()"
// with the function you want to solve.
// Use an object from this class in OneDimSolve
class R1_R1
{
// the prototype for a Real function of a Real variable
// you need to derive your function from this one and put in your
// function for operator() at least. You probably also want to set up a
// constructor to put in additional parameter values (e.g. that will not
// vary during a solve)
protected:
Real x; // Current x value
bool xSet; // true if a value assigned to x
public:
Real minX, maxX; // range of value x
bool minXinf, maxXinf; // true if these are infinite
R1_R1() : xSet(false), minXinf(true), maxXinf(true) {}
virtual Real operator()() = 0; // function value at current x
// set current x
virtual void Set(Real X); // set x, check OK
Real operator()(Real X) { Set(X); return operator()(); }
// set x, return value
virtual bool IsValid(Real X);
operator Real(); // implicit conversion
virtual ~R1_R1() {} // to keep gnu happy
};
class SolutionException : public BaseException
{
public:
static unsigned long Select;
SolutionException(const char* a_what = 0);
};
class OneDimSolve
{
R1_R1& function; // reference to the function
Real accX; // accuracy in X direction
Real accY; // accuracy in Y direction
int lim; // maximum number of iterations
public:
OneDimSolve(R1_R1& f, Real AccY = 0.0001, Real AccX = 0.0)
: function(f), accX(AccX), accY(AccY) {}
// f is an R1_R1 function
Real Solve(Real Y, Real X, Real Dev, int Lim=100);
// Solve for x in Y=f(x)
// X is the initial trial value of x
// X+Dev is the second trial value
// program returns a value of x such that
// |Y-f(x)| <= accY or |f.inv(Y)-x| <= accX
private:
Real x[3], y[3]; // Trial values of X and Y
int L,C,U,Last; // Locations of trial values
int vpol, hpol; // polarities
Real YY; // target value
int i;
void LookAt(int); // get new value of function
bool Finish; // true if LookAt finds conv.
bool Captured; // true when target surrounded
void VFlip();
void HFlip();
void Flip();
void State(int I, int J, int K);
void Linear(int, int, int);
void Quadratic(int, int, int);
};
#ifdef use_namespace
}
#endif
// body file: solution.cpp