Imagery library - functions for wx.iclass. More...

#include <math.h>
#include <grass/imagery.h>
#include <grass/glocale.h>
#include <grass/colors.h>
#include "iclass_local_proto.h"

Include dependency graph for iclass_statistics.c:

Go to the source code of this file.

Functions
void	I_iclass_init_statistics (IClass_statistics statistics, int category, const char name, const char *color, float nstd)
	Initialize statistics. More...

void	alloc_statistics (IClass_statistics *statistics, int nbands)
	Allocate space for statistics. More...

void	I_iclass_free_statistics (IClass_statistics *statistics)
	Free space allocated for statistics attributes. More...

int	make_all_statistics (IClass_statistics statistics, IClass_perimeter_list perimeters, CELL *band_buffer, int band_fd)
	Calculate statistics for all training areas. More...

int	make_statistics (IClass_statistics statistics, IClass_perimeter perimeter, CELL *band_buffer, int band_fd)
	Calculate statistics for one training area. More...

void	create_raster (IClass_statistics statistics, CELL band_buffer, int band_fd, const char *raster_name)
	Create raster map based on statistics. More...

void	band_range (IClass_statistics *statistics, int band)
	Helper function for computing min and max range in one band. More...

float	mean (IClass_statistics *statistics, int band)
	Helper function for computing mean. More...

float	stddev (IClass_statistics *statistics, int band)
	Helper function for standard deviation. More...

float	var (IClass_statistics *statistics, int band1, int band2)
	Helper function for computing variance. More...

float	var_signature (IClass_statistics *statistics, int band1, int band2)
	Helper function for computing variance for signature file. More...

void	I_iclass_statistics_get_nbands (IClass_statistics statistics, int nbands)
	Get number of bands. More...

void	I_iclass_statistics_get_cat (IClass_statistics statistics, int cat)
	Get category (class). More...

void	I_iclass_statistics_get_name (IClass_statistics statistics, const char *name)
	Get category (class) name. More...

void	I_iclass_statistics_get_color (IClass_statistics statistics, const char *color)
	Get category (class) color. More...

void	I_iclass_statistics_get_ncells (IClass_statistics statistics, int ncells)
	Get number of cells in training areas. More...

void	I_iclass_statistics_get_nstd (IClass_statistics statistics, float nstd)
	Get the multiplier of standard deviation. More...

void	I_iclass_statistics_set_nstd (IClass_statistics *statistics, float nstd)
	Set the multiplier of standard deviation. More...

int	I_iclass_statistics_get_min (IClass_statistics statistics, int band, int min)
	Get minimum value in band. More...

int	I_iclass_statistics_get_max (IClass_statistics statistics, int band, int max)
	Get maximum value in band. More...

int	I_iclass_statistics_get_sum (IClass_statistics statistics, int band, float sum)
	Get sum of values in band. More...

int	I_iclass_statistics_get_mean (IClass_statistics statistics, int band, float mean)
	Get mean of cell category values in band. More...

int	I_iclass_statistics_get_stddev (IClass_statistics statistics, int band, float stddev)
	Get standard deviation of cell category values in band. More...

int	I_iclass_statistics_get_histo (IClass_statistics statistics, int band, int cat, int value)
	Get histogram value in band. More...

int	I_iclass_statistics_get_product (IClass_statistics statistics, int band1, int band2, float value)
	Get product value. More...

int	I_iclass_statistics_get_range_min (IClass_statistics statistics, int band, int min)
	Get minimum cell value based on mean and standard deviation for band. More...

int	I_iclass_statistics_get_range_max (IClass_statistics statistics, int band, int max)
	Get maximum cell value based on mean and standard deviation for band. More...

Detailed Description

Imagery library - functions for wx.iclass.

Computation based on training areas for supervised classification. Based on i.class module (GRASS 6).

Computation and writing signatures to file.

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

Author: David Satnik, Central Washington University (original author); Markus Neteler <neteler itc.it> (i.class module); Bernhard Reiter <bernhard intevation.de> (i.class module); Brad Douglas <rez touchofmadness.com>(i.class module); Glynn Clements <glynn gclements.plus.com> (i.class module); Hamish Bowman <hamish_b yahoo.com> (i.class module); Jan-Oliver Wagner <jan intevation.de> (i.class module); Anna Kratochvilova <kratochanna gmail.com> (rewriting for wx.iclass); Vaclav Petras <wenzeslaus gmail.com> (rewriting for wx.iclass)

Computation based on training areas for supervised classification. Based on i.class module (GRASS 6).

Computing statistical values (mean, min, max, ...) from given area perimeters for each band.

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

Author: David Satnik, Central Washington University (original author); Markus Neteler <neteler itc.it> (i.class module); Bernhard Reiter <bernhard intevation.de> (i.class module); Brad Douglas <rez touchofmadness.com>(i.class module); Glynn Clements <glynn gclements.plus.com> (i.class module); Hamish Bowman <hamish_b yahoo.com> (i.class module); Jan-Oliver Wagner <jan intevation.de> (i.class module); Anna Kratochvilova <kratochanna gmail.com> (rewriting for wx.iclass); Vaclav Petras <wenzeslaus gmail.com> (rewriting for wx.iclass)

Definition in file iclass_statistics.c.

Function Documentation

◆ alloc_statistics()

void alloc_statistics	(	IClass_statistics *	statistics,
		int	nbands
	)

Allocate space for statistics.

Parameters

statistics	pointer to statistics structure
nbands	number of band files

Definition at line 76 of file iclass_statistics.c.

References IClass_statistics::band_histo, IClass_statistics::band_max, IClass_statistics::band_mean, IClass_statistics::band_min, IClass_statistics::band_product, IClass_statistics::band_range_max, IClass_statistics::band_range_min, IClass_statistics::band_stddev, IClass_statistics::band_sum, G_calloc, G_debug(), and IClass_statistics::nbands.

Referenced by I_iclass_analysis().

◆ band_range()

void band_range	(	IClass_statistics *	statistics,
		int	band
	)

Helper function for computing min and max range in one band.

Computing min and max range value (distance from mean dependent on number od std ddevs).

Parameters

statistics	pointer to statistics structure
band	band index

Definition at line 350 of file iclass_statistics.c.

References IClass_statistics::band_mean, IClass_statistics::band_range_max, IClass_statistics::band_range_min, IClass_statistics::band_stddev, and IClass_statistics::nstd.

Referenced by I_iclass_create_raster(), and make_all_statistics().

◆ create_raster()

void create_raster	(	IClass_statistics *	statistics,
		CELL **	band_buffer,
		int *	band_fd,
		const char *	raster_name
	)

Create raster map based on statistics.

Parameters

statistics	pointer to statistics structure
band_buffer	buffer to read band rows into
band_fd	band files descriptors
raster_name	name of new raster map

Definition at line 282 of file iclass_statistics.c.

Referenced by I_iclass_analysis(), and I_iclass_create_raster().

◆ I_iclass_free_statistics()

void I_iclass_free_statistics ( IClass_statistics * statistics )

Free space allocated for statistics attributes.

Frees all allocated arrays in statistics structure.

Parameters

statistics pointer to statistics structure

Definition at line 108 of file iclass_statistics.c.

References IClass_statistics::band_histo, IClass_statistics::band_max, IClass_statistics::band_mean, IClass_statistics::band_min, IClass_statistics::band_product, IClass_statistics::band_range_max, IClass_statistics::band_range_min, IClass_statistics::band_stddev, IClass_statistics::band_sum, IClass_statistics::color, G_debug(), G_free(), IClass_statistics::name, and IClass_statistics::nbands.

◆ I_iclass_init_statistics()

void I_iclass_init_statistics	(	IClass_statistics *	statistics,
		int	category,
		const char *	name,
		const char *	color,
		float	nstd
	)

Initialize statistics.

Parameters

[out]	statistics	pointer to statistics structure
	category	category (class)
	name	class name
	color	class color
	nstd	standard deviation

Definition at line 45 of file iclass_statistics.c.

References IClass_statistics::band_histo, IClass_statistics::band_max, IClass_statistics::band_mean, IClass_statistics::band_min, IClass_statistics::band_product, IClass_statistics::band_range_max, IClass_statistics::band_range_min, IClass_statistics::band_stddev, IClass_statistics::band_sum, IClass_statistics::cat, IClass_statistics::color, G_debug(), G_store(), IClass_statistics::name, IClass_statistics::nbands, IClass_statistics::ncells, IClass_statistics::nstd, and NULL.

◆ I_iclass_statistics_get_cat()

void I_iclass_statistics_get_cat	(	IClass_statistics *	statistics,
		int *	cat
	)

Get category (class).

Parameters

	statistics	pointer to statistics structure
[out]	cat	category

Definition at line 475 of file iclass_statistics.c.

References IClass_statistics::cat.

◆ I_iclass_statistics_get_color()

void I_iclass_statistics_get_color	(	IClass_statistics *	statistics,
		const char **	color
	)

Get category (class) color.

Note: color is pointer to already allocated const char * in statistics. You should not free it.

Parameters

	statistics	pointer to statistics structure
[out]	color	category color

Definition at line 506 of file iclass_statistics.c.

References IClass_statistics::color.

◆ I_iclass_statistics_get_histo()

int I_iclass_statistics_get_histo	(	IClass_statistics *	statistics,
		int	band,
		int	cat,
		int *	value
	)

Get histogram value in band.

Each band has one value for each raster cell category. Value is number of cells in category.

Parameters

	statistics	pointer to statistics structure
	band	band index
	cat	raster cell category
[out]	value	number of cells in category

Returns: 1 on success; 0 band index or cell category value out of range

Definition at line 676 of file iclass_statistics.c.

References _, IClass_statistics::band_histo, G_warning(), and IClass_statistics::nbands.

◆ I_iclass_statistics_get_max()

int I_iclass_statistics_get_max	(	IClass_statistics *	statistics,
		int	band,
		int *	max
	)

Get maximum value in band.

Parameters

	statistics	pointer to statistics structure
	band	band index
[out]	max	maximum value

Returns: 1 on success; 0 band index out of range

Definition at line 580 of file iclass_statistics.c.

References _, IClass_statistics::band_max, G_warning(), and IClass_statistics::nbands.

◆ I_iclass_statistics_get_mean()

int I_iclass_statistics_get_mean	(	IClass_statistics *	statistics,
		int	band,
		float *	mean
	)

Get mean of cell category values in band.

Parameters

	statistics	pointer to statistics structure
	band	band index
[out]	mean	mean

Returns: 1 on success; 0 band index out of range

Definition at line 626 of file iclass_statistics.c.

References _, IClass_statistics::band_mean, G_warning(), and IClass_statistics::nbands.

◆ I_iclass_statistics_get_min()

int I_iclass_statistics_get_min	(	IClass_statistics *	statistics,
		int	band,
		int *	min
	)

Get minimum value in band.

Parameters

	statistics	pointer to statistics structure
	band	band index
[out]	min	minimum value

Returns: 1 on success; 0 band index out of range

Definition at line 557 of file iclass_statistics.c.

References _, IClass_statistics::band_min, G_warning(), and IClass_statistics::nbands.

◆ I_iclass_statistics_get_name()

void I_iclass_statistics_get_name	(	IClass_statistics *	statistics,
		const char **	name
	)

Get category (class) name.

Note: name is pointer to already allocated const char * in statistics. You should not free it.

Parameters

	statistics	pointer to statistics structure
[out]	name	category name

Definition at line 490 of file iclass_statistics.c.

References IClass_statistics::name.

◆ I_iclass_statistics_get_nbands()

void I_iclass_statistics_get_nbands	(	IClass_statistics *	statistics,
		int *	nbands
	)

Get number of bands.

Parameters

	statistics	pointer to statistics structure
[out]	nbands	number of bands

Definition at line 463 of file iclass_statistics.c.

References IClass_statistics::nbands.

◆ I_iclass_statistics_get_ncells()

void I_iclass_statistics_get_ncells	(	IClass_statistics *	statistics,
		int *	ncells
	)

Get number of cells in training areas.

Parameters

	statistics	pointer to statistics structure
[out]	ncells	number of cells

Definition at line 519 of file iclass_statistics.c.

References IClass_statistics::ncells.

◆ I_iclass_statistics_get_nstd()

void I_iclass_statistics_get_nstd	(	IClass_statistics *	statistics,
		float *	nstd
	)

Get the multiplier of standard deviation.

Parameters

	statistics	pointer to statistics structure
[out]	nstd	multiplier of standard deviation

Definition at line 531 of file iclass_statistics.c.

References IClass_statistics::nstd.

◆ I_iclass_statistics_get_product()

int I_iclass_statistics_get_product	(	IClass_statistics *	statistics,
		int	band1,
		int	band2,
		float *	value
	)

Get product value.

Product value of two bands is sum of products of cell category values of two bands. Only cells from training areas are taken into account.

Parameters

	statistics	statistics object
	band1	index of first band
	band2	index of second band
[out]	value	product value

Returns: 1 on success; 0 band index out of range

Definition at line 708 of file iclass_statistics.c.

References _, IClass_statistics::band_product, G_warning(), and IClass_statistics::nbands.

◆ I_iclass_statistics_get_range_max()

int I_iclass_statistics_get_range_max	(	IClass_statistics *	statistics,
		int	band,
		int *	max
	)

Get maximum cell value based on mean and standard deviation for band.

Parameters

	statistics	pointer to statistics structure
	band	band index
[out]	max	maximum value

Returns: 1 on success; 0 band index out of range

Definition at line 754 of file iclass_statistics.c.

References _, IClass_statistics::band_range_max, G_warning(), and IClass_statistics::nbands.

◆ I_iclass_statistics_get_range_min()

int I_iclass_statistics_get_range_min	(	IClass_statistics *	statistics,
		int	band,
		int *	min
	)

Get minimum cell value based on mean and standard deviation for band.

Parameters

	statistics	pointer to statistics structure
	band	band index
[out]	min	minimum value

Returns: 1 on success; 0 band index out of range

Definition at line 731 of file iclass_statistics.c.

References _, IClass_statistics::band_range_min, G_warning(), and IClass_statistics::nbands.

◆ I_iclass_statistics_get_stddev()

int I_iclass_statistics_get_stddev	(	IClass_statistics *	statistics,
		int	band,
		float *	stddev
	)

Get standard deviation of cell category values in band.

Parameters

	statistics	pointer to statistics structure
	band	band index
[out]	stddev	standard deviation

Returns: 1 on success; 0 band index out of range

Definition at line 649 of file iclass_statistics.c.

References _, IClass_statistics::band_stddev, G_warning(), and IClass_statistics::nbands.

◆ I_iclass_statistics_get_sum()

int I_iclass_statistics_get_sum	(	IClass_statistics *	statistics,
		int	band,
		float *	sum
	)

Get sum of values in band.

Parameters

	statistics	pointer to statistics structure
	band	band index
[out]	sum	sum

Returns: 1 on success; 0 band index out of range

Definition at line 603 of file iclass_statistics.c.

References _, IClass_statistics::band_sum, G_warning(), and IClass_statistics::nbands.

◆ I_iclass_statistics_set_nstd()

void I_iclass_statistics_set_nstd	(	IClass_statistics *	statistics,
		float	nstd
	)

Set the multiplier of standard deviation.

Parameters

statistics	pointer to statistics structure
nstd	multiplier of standard deviation

Definition at line 542 of file iclass_statistics.c.

References IClass_statistics::nstd.

◆ make_all_statistics()

int make_all_statistics	(	IClass_statistics *	statistics,
		IClass_perimeter_list *	perimeters,
		CELL **	band_buffer,
		int *	band_fd
	)

Calculate statistics for all training areas.

Parameters

statistics	pointer to statistics structure
perimeters	list of all area perimeters
band_buffer	buffer to read band rows into
band_fd	band files descriptors

Returns: 1 on succes; 0 on failure

Definition at line 144 of file iclass_statistics.c.

References b, IClass_statistics::band_histo, IClass_statistics::band_max, IClass_statistics::band_mean, IClass_statistics::band_min, IClass_statistics::band_product, band_range(), IClass_statistics::band_stddev, IClass_statistics::band_sum, G_debug(), make_statistics(), mean(), IClass_statistics::nbands, and stddev().

Referenced by I_iclass_analysis().

◆ make_statistics()

int make_statistics	(	IClass_statistics *	statistics,
		IClass_perimeter *	perimeter,
		CELL **	band_buffer,
		int *	band_fd
	)

Calculate statistics for one training area.

Parameters

[out]	statistics	pointer to statistics structure
	perimeter	area perimeter
	band_buffer	buffer to read band rows into
	band_fd	band files descriptors

Returns: 1 on succes; 0 on failure

Definition at line 195 of file iclass_statistics.c.

References b.

Referenced by make_all_statistics().

◆ mean()

float mean	(	IClass_statistics *	statistics,
		int	band
	)

Helper function for computing mean.

Computing mean value of cell category values in one band within training area.

Parameters

statistics	pointer to statistics structure
band	band index

Returns: mean value

Definition at line 372 of file iclass_statistics.c.

References IClass_statistics::band_sum, and IClass_statistics::ncells.

Referenced by Cdhc_anderson_darling(), Cdhc_anderson_darling_exp(), Cdhc_chi_square(), Cdhc_chi_square_exp(), Cdhc_cramer_von_mises(), Cdhc_cramer_von_mises_exp(), Cdhc_dmax(), Cdhc_dmax_exp(), Cdhc_omnibus_moments(), Cdhc_shapiro_wilk_exp(), Cdhc_watson_u2(), Cdhc_watson_u2_exp(), make_all_statistics(), N_compute_gradient_field_2d(), N_compute_gradient_field_3d(), P_Mean_Calc(), and var().

◆ stddev()

float stddev	(	IClass_statistics *	statistics,
		int	band
	)

Helper function for standard deviation.

Computing standard deviation of cell category values in one band within training area.

Parameters

statistics	pointer to statistics structure
band	band index

Returns: standard deviation

Definition at line 388 of file iclass_statistics.c.

References var().

Referenced by make_all_statistics().

◆ var()

float var	(	IClass_statistics *	statistics,
		int	band1,
		int	band2
	)

Helper function for computing variance.

Computing variance of cell category values in one band within training area.

Parameters

statistics	pointer to statistics structure
band1	band index
band2	band index

Returns: variance

See also: var_signature

Definition at line 407 of file iclass_statistics.c.

References IClass_statistics::band_product, mean(), and IClass_statistics::ncells.

Referenced by c_kurt(), c_stddev(), stddev(), w_kurt(), and w_stddev().

◆ var_signature()

float var_signature	(	IClass_statistics *	statistics,
		int	band1,
		int	band2
	)

Helper function for computing variance for signature file.

Computing variance of cell category values in one band within training area. Variance is computed in special way.

Parameters

statistics	pointer to statistics structure
band1	band index
band2	band index

Returns: variance

See also: var

Todo:: verify the computation

Definition at line 440 of file iclass_statistics.c.

References IClass_statistics::band_product, IClass_statistics::band_sum, and IClass_statistics::ncells.

Referenced by I_iclass_add_signature().

Functions

Detailed Description

Function Documentation

◆ alloc_statistics()

◆ band_range()

◆ create_raster()

◆ I_iclass_free_statistics()

◆ I_iclass_init_statistics()

◆ I_iclass_statistics_get_cat()

◆ I_iclass_statistics_get_color()

◆ I_iclass_statistics_get_histo()

◆ I_iclass_statistics_get_max()

◆ I_iclass_statistics_get_mean()

◆ I_iclass_statistics_get_min()

◆ I_iclass_statistics_get_name()

◆ I_iclass_statistics_get_nbands()

◆ I_iclass_statistics_get_ncells()

◆ I_iclass_statistics_get_nstd()

◆ I_iclass_statistics_get_product()

◆ I_iclass_statistics_get_range_max()

◆ I_iclass_statistics_get_range_min()

◆ I_iclass_statistics_get_stddev()

◆ I_iclass_statistics_get_sum()

◆ I_iclass_statistics_set_nstd()

◆ make_all_statistics()

◆ make_statistics()

◆ mean()

◆ stddev()

◆ var()

◆ var_signature()