area_sphere.c File Reference

#include <math.h>
#include <grass/gis.h>
#include "pi.h"

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Functions
int	G_begin_zone_area_on_sphere (double r, double s)
	initialize calculations for sphere
double	G_darea0_on_sphere (register double lat)
double	G_area_for_zone_on_sphere (register double north, register double south)
	area between latitudes

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Function Documentation

double G_area_for_zone_on_sphere	(	register double	north,
		register double	south
	)

area between latitudes

Returns the area between latitudes north and south scaled by the factor s passed to G_begin_zone_area_on_sphere.

Parameters:

	north
	south

Returns:

double

Definition at line 55 of file area_sphere.c.

References G_darea0_on_sphere().

int G_begin_zone_area_on_sphere	(	double	r,
		double	s
	)

initialize calculations for sphere

Initializes raster area calculations for a sphere. The radius of the sphere is r and s is a scale factor to allow for calculations of a part of the zone (see G_begin_zone_area_on_ellipsoid).

Parameters:

	r
	s

Returns:

int

Definition at line 24 of file area_sphere.c.

References PI.

Referenced by G_begin_cell_area_calculations().

double G_darea0_on_sphere

(

register double

lat

)

Definition at line 32 of file area_sphere.c.

References Radians, and sin().

Referenced by G_area_for_zone_on_sphere(), and G_begin_cell_area_calculations().