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#include <u.h>
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#include <libc.h>
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#include "map.h"
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static int
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Xlagrange(struct place *place, double *x, double *y)
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{
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	double z1,z2;
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	double w1,w2,t1,t2;
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	struct place p;
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	copyplace(place,&p);
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	if(place->nlat.l<0) {
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		p.nlat.l = -p.nlat.l;
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		p.nlat.s = -p.nlat.s;
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	}
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	Xstereographic(&p,&z1,&z2);
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	csqrt(-z2/2,z1/2,&w1,&w2);
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	cdiv(w1-1,w2,w1+1,w2,&t1,&t2);
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	*y = -t1;
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	*x = t2;
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	if(place->nlat.l<0)
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		*y = -*y;
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	return(1);
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}
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proj
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lagrange(void)
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{
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	return(Xlagrange);
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}