# SCIP

Solving Constraint Integer Programs

circle.c File Reference

## Detailed Description

Solving the Circle Enclosing Points Problem.

This example shows how to setup second-order-cone constraints in SCIP when using SCIP as callable library. The example implements a model for the computation of a smallest circle that contains a number of given points in the plane.

The model is taken from the GAMS model library: http://www.gams.com/modlib/libhtml/circle.htm

Given n points in the plane with coordinates $$(x_i, y_i)$$, the task is to find a coordinates $$(a,b)$$ and a minimal radius $$r \geq 0$$, such that $$\sqrt{(x_i-a)^2 + (y_i-b)^2} \leq r$$. The latter are second-order-cone constraints.

Definition in file circle.c.

#include <stdio.h>
#include "scip/pub_misc.h"
#include "scip/scip.h"
#include "scip/scipdefplugins.h"

Go to the source code of this file.

## Functions

static SCIP_RETCODE setupProblem (SCIP *scip, SCIP_RANDNUMGEN *randnumgen)

static SCIP_RETCODE runCircle (void)

int main (int argc, char **argv)

## Variables

static const int npoints = 10

static const unsigned int randseed = 42

## ◆ setupProblem()

 static SCIP_RETCODE setupProblem ( SCIP * scip, SCIP_RANDNUMGEN * randnumgen )
static

sets up problem

Parameters
 scip SCIP data structure randnumgen random number generator

Definition at line 50 of file circle.c.

Referenced by runCircle().

## ◆ runCircle()

 static SCIP_RETCODE runCircle ( void )
static

runs circle enclosing example

Definition at line 102 of file circle.c.

Referenced by main().

## ◆ main()

 int main ( int argc, char ** argv )

main method starting SCIP

Parameters
 argc number of arguments from the shell argv array of shell arguments

Definition at line 142 of file circle.c.

References runCircle(), SCIP_OKAY, and SCIPprintError().

## ◆ npoints

 const int npoints = 10
static

number of points to enclose by a circle

Definition at line 43 of file circle.c.

Referenced by applyHeur(), clusterPointsGreedy(), filterPoints(), setupProblem(), and solveNLP().

## ◆ randseed

 const unsigned int randseed = 42
static

seed for random number generator

Definition at line 46 of file circle.c.

Referenced by runCircle().