Functions

sample.c File Reference

GIS library - sampling methods (extract a cell value from raster map). More...

#include <string.h>
#include <unistd.h>
#include <math.h>
#include <grass/gis.h>
#include <grass/glocale.h>
Include dependency graph for sample.c:

Go to the source code of this file.

Functions

DCELL G_get_raster_sample (int fd, const struct Cell_head *window, struct Categories *cats, double north, double east, int usedesc, INTERP_TYPE itype)
 Extract a cell value from raster map.
DCELL G_get_raster_sample_nearest (int fd, const struct Cell_head *window, struct Categories *cats, double north, double east, int usedesc)
DCELL G_get_raster_sample_bilinear (int fd, const struct Cell_head *window, struct Categories *cats, double north, double east, int usedesc)
DCELL G_get_raster_sample_cubic (int fd, const struct Cell_head *window, struct Categories *cats, double north, double east, int usedesc)

Detailed Description

GIS library - sampling methods (extract a cell value from raster map).

1/2006: moved to libgis from v.sample/v.drape for clone removal

(C) 2001-2008 by the GRASS Development Team

This program is free software under the GNU General Public License (>=v2). Read the file COPYING that comes with GRASS for details.

Author:
James Darrell McCauley <darrell mccauley-usa.com>, http://mccauley-usa.com/
Date:
1994

Definition in file sample.c.


Function Documentation

DCELL G_get_raster_sample ( int  fd,
const struct Cell_head *  window,
struct Categories *  cats,
double  north,
double  east,
int  usedesc,
INTERP_TYPE  itype 
)

Extract a cell value from raster map.

Extract a cell value from raster map at given northing and easting with a sampled 3x3 window using a specified interpolation method.

Parameters:
fd file descriptor
window region settings
cats categories
north northing position
east easting position
usedesc flag to scan category label
itype interpolation method
Returns:
cell value at given position

Definition at line 50 of file sample.c.

References G_fatal_error(), G_get_raster_sample_bilinear(), G_get_raster_sample_cubic(), and G_get_raster_sample_nearest().

DCELL G_get_raster_sample_bilinear ( int  fd,
const struct Cell_head *  window,
struct Categories *  cats,
double  north,
double  east,
int  usedesc 
)
DCELL G_get_raster_sample_cubic ( int  fd,
const struct Cell_head *  window,
struct Categories *  cats,
double  north,
double  east,
int  usedesc 
)
DCELL G_get_raster_sample_nearest ( int  fd,
const struct Cell_head *  window,
struct Categories *  cats,
double  north,
double  east,
int  usedesc 
)