blob: 3284c495298735feb847737bbe49a28549ebe922 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
|
#include <u.h>
#include <libc.h>
#include "map.h"
static int
Xmollweide(struct place *place, double *x, double *y)
{
double z;
double w;
z = place->nlat.l;
if(fabs(z)<89.9*RAD)
do { /*newton for 2z+sin2z=pi*sin(lat)*/
w = (2*z+sin(2*z)-PI*place->nlat.s)/(2+2*cos(2*z));
z -= w;
} while(fabs(w)>=.00001);
*y = sin(z);
*x = - (2/PI)*cos(z)*place->wlon.l;
return(1);
}
proj
mollweide(void)
{
return(Xmollweide);
}
|