Generated on Wed Nov 5 2014 05:18:37 for Gecode by doxygen 1.7.6.1
GoldenSpiral Class Reference

Example: Golden spiral More...

List of all members.

Public Member Functions

 GoldenSpiral (const Options &)
 Actual model.
 GoldenSpiral (bool share, GoldenSpiral &p)
 Constructor for cloning p.
virtual Spacecopy (bool share)
 Copy during cloning.
virtual void constrain (const Space &_b)
 Add constraint to current model to get next solution (not too close)
virtual void print (std::ostream &os) const
 Print solution coordinates.

Protected Attributes

FloatVarArray f
 The numbers.
FloatNum step
 Minimum distance between two solutions.

Related Functions

(Note that these are not member functions.)

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

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 81 of file golden-spiral.cpp.


Constructor & Destructor Documentation

GoldenSpiral::GoldenSpiral ( const Options ) [inline]

Actual model.

Definition at line 89 of file golden-spiral.cpp.

GoldenSpiral::GoldenSpiral ( bool  share,
GoldenSpiral p 
) [inline]

Constructor for cloning p.

Definition at line 105 of file golden-spiral.cpp.


Member Function Documentation

virtual Space* GoldenSpiral::copy ( bool  share) [inline, virtual]

Copy during cloning.

Definition at line 110 of file golden-spiral.cpp.

virtual void GoldenSpiral::constrain ( const Space _b) [inline, virtual]

Add constraint to current model to get next solution (not too close)

Definition at line 114 of file golden-spiral.cpp.

virtual void GoldenSpiral::print ( std::ostream &  os) const [inline, virtual]

Print solution coordinates.

Reimplemented from Gecode::Driver::ScriptBase< BaseSpace >.

Definition at line 119 of file golden-spiral.cpp.


Friends And Related Function Documentation

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

Main-function.

Definition at line 129 of file golden-spiral.cpp.


Member Data Documentation

The numbers.

Definition at line 84 of file golden-spiral.cpp.

Minimum distance between two solutions.

Definition at line 86 of file golden-spiral.cpp.


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