Circle*
triangle_circumcircle(Triangle *t)
{
if (t->circumcircle->radius) {
Point *center = triangle_circumcenter(t);
t->circumcircle = circle_new(center, triangle_circumcircle_radius(t, center));
free(center);
}
return t->circumcircle;
}
void test21011 ( )
/******************************************************************************/
/*
Purpose:
TEST21011 tests TRIANGLE_CIRCUMCENTER.
Licensing:
This code is distributed under the GNU LGPL license.
Modified:
28 October 2010
Author:
John Burkardt
*/
{
# define M1 2
# define TEST_NUM 4
double *a12;
int i;
int j;
int k;
int m2;
double *o1;
double *o2;
int m1 = M1;
double pc1[M1];
double *pc2;
int seed;
double t1[M1*3];
double *t2;
double t_test[M1*3*TEST_NUM] = {
10.0, 5.0,
11.0, 5.0,
10.0, 6.0,
10.0, 5.0,
11.0, 5.0,
10.5, 5.86602539,
10.0, 5.0,
11.0, 5.0,
10.5, 15.0,
10.0, 5.0,
11.0, 5.0,
20.0, 7.0 };
int test;
int test_num = TEST_NUM;
printf ( "\n" );
printf ( "TEST21011\n" );
printf ( " For a triangle in M dimensions, the circumenter can be computed by:\n" );
printf ( " TRIANGLE_CIRCUMCENTER;\n" );
//
// Vary the dimension.
//
for ( m2 = 2; m2 <= 5; m2++ )
{
seed = 123456789;
printf ( "\n" );
printf ( " M2 = %d\n", m2 );
t2 = ( double * ) malloc ( m2 * 3 * sizeof ( double ) );
//
// Randomly choose a mapping P2 = O2 + A12 * ( P1 - O1 )
//
a12 = r8mat_uniform_01_new ( m2, m1, &seed );
o1 = r8vec_uniform_01_new ( m1, &seed );
o2 = r8vec_uniform_01_new ( m2, &seed );
//
// Map each M1-dimensional triangle into M2 space.
//
for ( test = 0; test < test_num; test++ )
{
for ( j = 0; j < 3; j++ )
{
for ( i = 0; i < m1; i++ )
{
t1[i+j*m1] = t_test[i+j*m1+test*m1*3];
}
}
for ( j = 0; j < 3; j++ )
{
t1[i+j*m1] = t1[i+j*m1] - o1[i];
}
for ( j = 0; j < 3; j++ )
{
for ( i = 0; i < m2; i++ )
{
t2[i+j*m2] = 0.0;
for ( k = 0; k < m1; k++ )
{
t2[i+j*m2] = t2[i+j*m2] + a12[i+k*m2] * t1[k+j*m1];
}
}
}
for ( j = 0; j < 3; j++ )
{
for ( i = 0; i < m2; i++ )
{
t2[i+j*m2] = t2[i+j*m2] + o2[i];
}
}
pc2 = triangle_circumcenter ( m2, t2 );
r8vec_print ( m2, pc2, " Circumcenter by TRIANGLE_CIRCUMCENTER:" );
printf ( "\n" );
printf ( " Distances from circumcenter to vertices:\n" );
printf ( "\n" );
for ( j = 0; j < 3; j++ )
{
printf ( " %f\n", r8vec_norm_affine ( m2, pc2, t2+j*m2 ) );
}
free ( pc2 );
}
free ( a12 );
free ( o1 );
free ( o2 );
free ( t2 );
}
return;
}
void test2101 ( )
/******************************************************************************/
/*
Purpose:
TEST2101 tests TRIANGLE_CIRCUMCENTER_2D and others.
Discussion:
The functions tested include
* TRIANGLE_CIRCUMCENTER_2D;
* TRIANGLE_CIRCUMCENTER_2D_2;
* TRIANGLE_CIRCUMCENTER.
Licensing:
This code is distributed under the GNU LGPL license.
Modified:
28 October 2010
Author:
John Burkardt
*/
{
# define M 2
# define TEST_NUM 4
int i;
int j;
int m = M;
double *pc;
double t[M*3];
double t_test[M*3*TEST_NUM] = {
10.0, 5.0,
11.0, 5.0,
10.0, 6.0,
10.0, 5.0,
11.0, 5.0,
10.5, 5.86602539,
10.0, 5.0,
11.0, 5.0,
10.5, 15.0,
10.0, 5.0,
11.0, 5.0,
20.0, 7.0 };
int test;
int test_num = TEST_NUM;
printf ( "\n" );
printf ( "TEST2101\n" );
printf ( " For a triangle in 2D, the circumenter can be computed by:\n" );
printf ( " TRIANGLE_CIRCUMCENTER_2D;\n" );
printf ( " TRIANGLE_CIRCUMCENTER_2D_2;\n" );
printf ( " TRIANGLE_CIRCUMCENTER (any dimension);\n" );
for ( test = 0; test < test_num; test++ )
{
for ( j = 0; j < 3; j++ )
{
for ( i = 0; i < m; i++ )
{
t[i+j*m] = t_test[i+j*m+test*m*3];
}
}
r8mat_transpose_print ( m, 3, t, " Triangle vertices:" );
pc = triangle_circumcenter_2d ( t );
r8vec_print ( m, pc, " Circumcenter by TRIANGLE_CIRCUMCENTER_2D:" );
free ( pc );
pc = triangle_circumcenter_2d_2 ( t );
r8vec_print ( m, pc, " Circumcenter by TRIANGLE_CIRCUMCENTER_2D_2:" );
free ( pc );
pc = triangle_circumcenter ( m, t );
r8vec_print ( m, pc, " Circumcenter by TRIANGLE_CIRCUMCENTER:" );
free ( pc );
}
return;
# undef M
# undef TEST_NUM
}