bool EnvEntrance::Near(const QVector3D & p, const float dist) const
{
QVector3D midpt(bx1+bx2+1, p.y(), by1+by2+1);
midpt *= 0.5f;
return (p-midpt).lengthSquared() < dist*dist;
}
int main() {
pt pt1 = {}, pt2 = {}, *p_pt = NULL;
printf("请输入一个点的位置：");
scanf("%d%d", &(pt1.y), &(pt1.x));
printf("请输入一个点的位置：");
scanf("%d%d", &(pt2.y), &(pt2.x));
midpt(&pt1, &pt2, p_pt);
if (p_pt) {
printf("中点位置是(%d, %d)\n", p_pt->y, p_pt->x);
free(p_pt);
p_pt = NULL;
}
return 0;
}
std::vector<double>
crk4(class Container1<functor_type>::iterator funct_iter1,
class Container1<functor_type>::iterator funct_iter2,
class Container2<coord_type>::iterator coord_iter1,
class Container2<coord_type>::iterator coord_iter2,
t_type t,
double h)
{
auto k1 = init(funct_iter1, funct_iter2, coord_iter1, coord_iter2, t);
auto m1 = midpt(k1, coord_iter1, h);
t += 0.5*h;
auto k2 = init(funct_iter1, funct_iter2, coord_iter1, coord_iter2, t);
auto m2 = midpt(k1, coord_iter1, h);
auto k3 = init(funct_iter1, funct_iter2, coord_iter1, coord_iter2, t);
auto m3 = midpt(k1, coord_iter1, h);
t += 0.5*h;
auto k4 = init(funct_iter1, funct_iter2, coord_iter1, coord_iter2, t);
auto coord_next = runge_kutta4(coord_iter1, coord_iter2,
k1.begin(), k2.begin(), k3.begin(), k4.begin(),
h);
return coord_next;
}
bool generateLinearSeparation(std::vector<point>& inputPoints,
double& a,
double& b,
double& c,
int& nBad1,
int& nBad2,
point& centroidOne,
point& centroidTwo)
{
int numOne=0, numTwo=0;
for (std::vector<point>::iterator pt = inputPoints.begin(); pt != inputPoints.end(); pt++)
{
if (pt->isClassOne)
{
numOne++;
centroidOne.x += pt->x;
centroidOne.y += pt->y;
}
else
{
numTwo++;
centroidTwo.x += pt->x;
centroidTwo.y += pt->y;
}
}
centroidOne.x /= numOne;
centroidOne.y /= numOne;
centroidTwo.x /= numTwo;
centroidTwo.y /= numTwo;
outputPoint(centroidOne);
outputPoint(centroidTwo);
point midpt(
(centroidTwo.x+centroidOne.x)/2,
(centroidTwo.y+centroidOne.y)/2);
outputPoint(midpt);
//direction vector
point oneToTwo(
centroidTwo.x-centroidOne.x,
centroidTwo.y-centroidOne.y);
double mag = distance(oneToTwo,point(0,0,false));
std::cerr << mag << std::endl;
oneToTwo.x /= mag;
oneToTwo.y /= mag;
//actual direction
point bisector(oneToTwo.x,oneToTwo.y);
outputPoint(bisector);
b = bisector.y;
a = bisector.x;
c = -(a*midpt.x+b*midpt.y);
for (std::vector<point>::iterator pt = inputPoints.begin(); pt != inputPoints.end(); pt++)
{
if(pt->isClassOne)
{
if(SGN(a*pt->x+b*pt->y+c) != SGN(a*centroidOne.x+b*centroidOne.y+c))
nBad1++;
}
else
{
if(SGN(a*pt->x+b*pt->y+c) != SGN(a*centroidTwo.x+b*centroidTwo.y+c))
nBad2++;
}
}
return true;
}
