c++实现 给定直角停车位两个点,求取剩余两点坐标。
//2018-09-08-fourmi /*************************include head files************************************************/ #include<iostream> #include<math.h> #include<vector> #include<cmath> #include<iomanip> #include<cstdlib> #include<cstring> #include<fstream> /*******************************************************************************************/ /**********************Define variables*****************************************************/ #define pi 3.1415926 #define POINT pair<double,double> #define VECT vector<vector<double> > const int MAX_ITER=100000; const double eps=0.0000001; /*******************************************************************************************/ using namespace std; /*****************************Vector_Transformation****************************************/ POINT Vector_Transformation(POINT &pt,double num1,double num2,double num3,double num4) { POINT result; result.first=pt.first*num1+pt.second*num3; result.second=pt.first*num2+pt.second*num4; return result; } /*******************************************************************************************/ /***************************FUNCTIONS_ABOUT_SVD*********************************************/ double get_norm(double *x, int n){ double r=0; for(int i=0;i<n;i++) r+=x[i]*x[i]; return sqrt(r); } double normalize(double *x, int n){ double r=get_norm(x,n); if(r<eps) return 0; for(int i=0;i<n;i++) x[i]/=r; return r; } inline double product(double*a, double *b,int n){ double r=0; for(int i=0;i<n;i++) r+=a[i]*b[i]; return r; } void orth(double *a, double *b, int n){//|a|=1 double r=product(a,b,n); for(int i=0;i<n;i++) b[i]-=r*a[i]; } bool svd(VECT A, int K, VECT &U, vector<double> &S, VECT &V){ int M=A.size(); int N=A[0].size(); double *left_vector=new double[M]; double *next_left_vector=new double[M]; double *right_vector=new double[N]; double *next_right_vector=new double[N]; double diff=1; double r=-1; int col=0; U.clear(); V.clear(); S.clear(); S.resize(K,0); U.resize(K); for(int i=0;i<K;i++) U[i].resize(M,0); V.resize(K); for(int i=0;i<K;i++) V[i].resize(N,0); for(int col=0;col<K;col++){ while(1){ for(int i=0;i<M;i++) left_vector[i]= (float)rand() / RAND_MAX; if(normalize(left_vector, M)>eps) break; } for(int iter=0;diff>=eps && iter<MAX_ITER;iter++){ memset(next_left_vector,0,sizeof(double)*M); memset(next_right_vector,0,sizeof(double)*N); for(int i=0;i<M;i++) for(int j=0;j<N;j++) next_right_vector[j]+=left_vector[i]*A[i][j]; r=normalize(next_right_vector,N); if(r<eps) break; for(int i=0;i<col;i++) orth(&V[i][0],next_right_vector,N); normalize(next_right_vector,N); for(int i=0;i<M;i++) for(int j=0;j<N;j++) next_left_vector[i]+=next_right_vector[j]*A[i][j]; r=normalize(next_left_vector,M); if(r<eps) break; for(int i=0;i<col;i++) orth(&U[i][0],next_left_vector,M); normalize(next_left_vector,M); diff=0; for(int i=0;i<M;i++){ double d=next_left_vector[i]-left_vector[i]; diff+=d*d; } memcpy(left_vector,next_left_vector,sizeof(double)*M); memcpy(right_vector,next_right_vector,sizeof(double)*N); } if(r>=eps){ S[col]=r; memcpy((char *)&U[col][0],left_vector,sizeof(double)*M); memcpy((char *)&V[col][0],right_vector,sizeof(double)*N); }else{ cout<<r<<endl; break; } } delete [] next_left_vector; delete [] next_right_vector; delete [] left_vector; delete [] right_vector; return true; } /*******************************************************************************************/ /**********************GET_THE_BIGGEST_SINGULAR_VALUE***************************************/ vector<double> GET_THE_BIGGEST_SINGULAR_VALUE(POINT vec,int m,int n,int k) { //分解一个1*2的矩阵A,求其前1个奇异值和奇异向量 VECT A; A.resize(m); for(int i=0;i<m;i++) { A[i].resize(n); } A[0][0]=vec.first; A[0][1]=vec.second; VECT U; vector<double> S; VECT V; svd(A,k,U,S,V); return S; } /*******************************************************************************************/ /************************CAL_THIRD_AND_FORTH_POINTS*****************************************/ POINT * cal_reset_TWO_points(POINT &pt1,POINT &pt2) { static POINT arr[2]; POINT vecFromSecToFirst,vec,pt3,pt4; int x1,y1,x2,y2,exemplarStart,exemplarEnd; double distance,angle,s,sideLength; double slantAngleInRadians = (double(90)/180)*pi; double LongSideMin=47.9042; double verticalPSSideLength=195; double parallelPSSideLength=83; int matrix_rows=1; int matrix_cols=2; int top_k_max=1; x1=pt1.first; y1=pt1.second; x2=pt2.first; y2=pt2.second; distance = sqrt(pow((x1-x2),2)+pow((y1-y2),2)); if (distance < LongSideMin) //说明是短库位 sideLength = verticalPSSideLength; else //说明是平行长库位 sideLength = parallelPSSideLength; vecFromSecToFirst.first=pt1.first-pt2.first; vecFromSecToFirst.second=pt1.second-pt2.second; vec=Vector_Transformation(vecFromSecToFirst,cos(slantAngleInRadians),-sin(slantAngleInRadians), sin(slantAngleInRadians), cos(slantAngleInRadians)); if ((pt2.first-pt1.first)==0) { angle=pi/2; } else { angle=abs(atan2(vecFromSecToFirst.second,vecFromSecToFirst.first)); } s=GET_THE_BIGGEST_SINGULAR_VALUE(vec,matrix_rows,matrix_cols,top_k_max)[0]; vec.first=vec.first/s; vec.second=vec.second/s; pt3.first=pt2.first+vec.first*sideLength; pt3.second=pt2.second+vec.second*sideLength; pt4.first=pt1.first+vec.first*sideLength; pt4.second=pt1.second+vec.second*sideLength; arr[0]=pt3; arr[1]=pt4; return arr; } /*******************************************************************************************/ /*****************************************MAIN()********************************************/ int main() { POINT * arr; POINT pt1(171,145); POINT pt2(171,213); arr=cal_reset_TWO_points(pt1,pt2); std::cout<<arr[0].first<<" "<<arr[0].second<<std::endl; std::cout<<arr[1].first<<" "<<arr[1].second<<std::endl; return 0; } /*******************************************************************************************/