北京54坐标和经纬度坐标转换算法(C++)

//坐标正算lbxy(doublel,doubleb,double*x,double*y,intl0){doublesa,sb,sep,sn,sy2,st,sm,sx,hb;doublexx,yy,hd,sd;//判断值的范围if(l360||l0||b360||b0){*x=l;*y=b;return;}l=l-l0;sa=6378245;sb=6356863.019;sep=0.006738525415;hd=b*PI;hb=hd/180.0;st=tan(hb);sn=pow(sa,(double)2)/sqrt(pow(sa,(double)2)*pow(cos(hb),(double)2)+pow(sb,(double)2)*pow(sin(hb),(double)2));sy2=sep*pow(cos(hb),(double)2);sd=cos(hb)*l*PI;sm=sd/180.0;sx=111134.861*b-(32005.78*sin(hb)+133.924*pow(sin(hb),(double)3)+0.697*pow(sin(hb),(double)5))*cos(hb);xx=sx+sn*st*(0.5*pow(sm,(double)2)+1.0/24.0*(5.0-pow(st,(double)2)+9.0*sy2)*pow(sm,(double)4));yy=sn*(sm+1.0/6.0*(1.0-pow(st,(double)2)+sy2)*pow(sm,(double)3)+1.0/120.0*(5.0-18.0*pow(st,(double)2)+pow(st,(double)4))*pow(sm,(double)5));*x=xx;*y=yy+500000;}//坐标反算xylb(doublel0,doublex,doubley,double*l,double*b){doublebf,vf,nf,ynf,tf,yf2,hbf;doublesa,sb,se2,sep2,mf;doublew1,w2,w,w3,w4;doublepi=3.1415926;x=x/1000000.0;y=y-500000.0;bf=9.04353692458*x-0.00001007623*pow(x,2.0)-0.00074438304*pow(x,3.0)-0.00000463064*pow(x,4.0)+0.00000505846*pow(x,5.0)-0.00000016754*pow(x,6.0);hbf=bf*pi/180.0;sa=6378245.0;sb=6356863.019;se2=0.006693421623;sep2=0.006738525415;w1=sin(hbf);w2=1.0-se2*pow(w1,(double)2);w=sqrt(w2);mf=sa*(1.0-se2)/pow(w,(double)3);w3=cos(hbf);w4=pow(sa,(double)2)*pow(w3,(double)2)+pow(sb,(double)2)*pow(w1,(double)2);nf=pow(sa,(double)2)/sqrt(w4);ynf=y/nf;vf=nf/mf;tf=tan(hbf);yf2=sep2*pow(w3,(double)2);*b=bf-1.0/2.0*vf*tf*(pow(ynf,(double)2)-1.0/12.0*(5.0+3.0*pow(tf,(double)2)+yf2-9.0*yf2*pow(tf,(double)2))*pow(ynf,(double)4))*180.0/pi;*l=1.0/w3*ynf*(1.0-1.0/6.0*(1.0+2.0*pow(tf,(double)2)+yf2)*pow(ynf,(double)2)+1.0/120.0*(5.0+28.0*pow(tf,(double)2)+24.0*pow(tf,(double)2)+6.0*yf2+8.0*yf2*pow(tf,(double)2))*pow(ynf,(double)4))*180.0/pi;*l=l0+*l;}