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Example: Golden spiral More...

Public Member Functions

 GoldenSpiral (const Options &opt)
 Actual model.
 GoldenSpiral (GoldenSpiral &p)
 Constructor for cloning p.
virtual Spacecopy (void)
 Copy during cloning.
virtual FloatVar cost (void) const
 Cost function.
virtual void print (std::ostream &os) const
 Print solution coordinates.
Public Member Functions inherited from Gecode::Driver::ScriptBase< Driver::ExtractStepOption< FloatMaximizeSpace > >
 ScriptBase (const Options &opt)
 Constructor.
 ScriptBase (ScriptBase &e)
 Constructor used for cloning.
virtual void compare (const Space &home, std::ostream &os) const
 Compare with s.
Public Member Functions inherited from Gecode::Driver::ExtractStepOption< BaseSpace >
 ExtractStepOption (const Options &opt)
 Constructor that extracts the step value.
 ExtractStepOption (BaseSpace &e)
 Constructor used for cloning.

Protected Attributes

FloatVarArray f
 The numbers.

(Note that these are not member symbols.)

int main (int argc, char *argv[])
 Main-function.

Additional Inherited Members

Static Public Member Functions inherited from Gecode::Driver::ScriptBase< Driver::ExtractStepOption< FloatMaximizeSpace > >
static std::ostream & select_ostream (const char *sn, std::ofstream &ofs)
 Choose output stream according to sn.
static void run (const Options &opt, Script *s=NULL)

Detailed Description

Example: Golden spiral

The Golden Spiral is a logarithmic spiral whose growth factor is the golden ratio $\phi=1,618$.

It is defined by the polar equation:

\[r = ae^{b\theta}
\]

where

\[\operatorname{abs}(b) = \frac{\operatorname{ln}(\phi)}{\frac{\pi}{2}}
\]

To get cartesian coordinates, it can be solved for $x$ and $y$ in terms of $r$ and $\theta$. By setting $a=1$, it yields to the equation:

\[r = e^{0.30649\times\theta}
\]

with

\[x=r\operatorname{cos}(\theta), \quad y=r\operatorname{sin}(\theta)
\]

The tuple $(r,\theta)$ is related to the position for $x$ and $y$ on the curve. $r$ and $\theta$ are positive numbers.

To get reasonable interval starting sizes, $x$ and $y$ are restricted to $[-20;20]$.

Definition at line 77 of file golden-spiral.cpp.

Constructor & Destructor Documentation

◆ GoldenSpiral() [1/2]

GoldenSpiral::GoldenSpiral ( const Options & opt)
inline

Actual model.

Definition at line 83 of file golden-spiral.cpp.

◆ GoldenSpiral() [2/2]

GoldenSpiral::GoldenSpiral ( GoldenSpiral & p)
inline

Constructor for cloning p.

Definition at line 99 of file golden-spiral.cpp.

Member Function Documentation

◆ copy()

virtual Space * GoldenSpiral::copy ( void )
inlinevirtual

Copy during cloning.

Definition at line 104 of file golden-spiral.cpp.

◆ cost()

virtual FloatVar GoldenSpiral::cost ( void ) const
inlinevirtual

Cost function.

Definition at line 108 of file golden-spiral.cpp.

◆ print()

virtual void GoldenSpiral::print ( std::ostream & os) const
inlinevirtual

Print solution coordinates.

Reimplemented from Gecode::Driver::ScriptBase< Driver::ExtractStepOption< FloatMaximizeSpace > >.

Definition at line 112 of file golden-spiral.cpp.

◆ main()

int main ( int argc,
char * argv[] )
related

Main-function.

Definition at line 122 of file golden-spiral.cpp.

Member Data Documentation

◆ f

FloatVarArray GoldenSpiral::f
protected

The numbers.

Definition at line 80 of file golden-spiral.cpp.


The documentation for this class was generated from the following file: