1 #include <u.h> 2 #include <libc.h> 3 #include "map.h" 4 5 static int Xmollweide(struct place * place,double * x,double * y)6Xmollweide(struct place *place, double *x, double *y) 7 { 8 double z; 9 double w; 10 z = place->nlat.l; 11 if(fabs(z)<89.9*RAD) 12 do { /*newton for 2z+sin2z=pi*sin(lat)*/ 13 w = (2*z+sin(2*z)-PI*place->nlat.s)/(2+2*cos(2*z)); 14 z -= w; 15 } while(fabs(w)>=.00001); 16 *y = sin(z); 17 *x = - (2/PI)*cos(z)*place->wlon.l; 18 return(1); 19 } 20 21 proj mollweide(void)22mollweide(void) 23 { 24 return(Xmollweide); 25 } 26