DEM is a digital elevation model class. More...

#include <dem.h>

Inheritance diagram for DEM:

Public Member Functions
	DEM (const QString &fileName)

bool	loadFromFile (const QString &fileName)
	loads a DEM from a ESRI style text file. More...

void	createSlopeGrid () const

const FloatGrid *	aspectGrid () const

const FloatGrid *	slopeGrid () const

const FloatGrid *	viewGrid () const

float	elevation (const float x, const float y) const
	get the elevation (m) at point (x/y) More...

float	elevation (const QPointF p) const

float	direction (const float x, const float y)
	get the direction of the slope at point (x/y) if the slope at the point is 0, "north" (0) is returned. More...

float	slope (const float x, const float y)

float	orientation (const QPointF &point, float &rslope_angle, float &rslope_aspect) const
	get orientation at specific point (x,y) and height More...

float	orientation (const float x, const float y, float &rslope_angle, float &rslope_aspect)

Public Member Functions inherited from Grid< float >
	Grid ()

	Grid (float cellsize, int sizex, int sizey)

	Grid (const QRectF rect_metric, const float cellsize)
	create from a metric rect More...

	Grid (const Grid< float > &toCopy)

bool	loadGridFromFile (const QString &fileName)
	load a grid from an ASCII grid file the coordinates and cell size remain as in the grid file. More...

	~Grid ()

void	clear ()

bool	setup (const float cellsize, const int sizex, const int sizey)

bool	setup (const QRectF &rect, const double cellsize)

bool	setup (const Grid< float > &source)

void	initialize (const float &value)

void	wipe ()
	write 0-bytes with memcpy to the whole area More...

void	wipe (const float value)
	overwrite the whole area with "value" size of T must be the size of "int" ERRORNOUS!!! More...

void	copy (const Grid< float > &source)
	copies the content of the source grid to this grid. More...

Grid< double > *	toDouble () const
	create a double grid (same size as this grid) and convert this grid to double values. More...

int	sizeX () const

int	sizeY () const

float	metricSizeX () const

float	metricSizeY () const

QRectF	metricRect () const
	get the metric rectangle of the grid More...

void	setMetricRect (QRectF rect)
	set the metric rectangle. Use with care! No further checks are executed! More...

QRect	rectangle () const
	get the rectangle of the grid in terms of indices More...

float	cellsize () const
	get the length of one pixel of the grid More...

int	count () const
	returns the number of elements of the grid More...

bool	isEmpty () const
	returns false if the grid was not setup More...

const float &	operator() (const int ix, const int iy) const
	access (const) with index variables. use int. More...

const float &	operator() (const float x, const float y) const
	access (const) using metric variables. use float. More...

const float &	operator[] (const QPoint &p) const
	access value of grid with a QPoint More...

float &	operator[] (const int idx) const
	use the square brackets to access by index More...

float &	operator[] (const QPointF &p)
	use the square bracket to access by QPointF More...

float &	operator[] (const QPoint &p)
	use the square bracket to access by QPoint More...

float &	valueAtIndex (const QPoint &pos)
	value at position defined by a QPoint defining the two indices (x,y) More...

float &	valueAtIndex (const int ix, const int iy)
	const value at position defined by indices (x,y) More...

float &	valueAtIndex (const int index)
	get a ref ot value at (one-dimensional) index 'index'. More...

int	index (const int ix, const int iy)
	get the 0-based index of the cell with indices ix and iy. More...

int	index (const QPoint &pos)
	get the 0-based index of the cell at 'pos'. More...

const float &	constValueAtIndex (const QPoint &pos) const
	value at position defined by a (integer) QPoint More...

const float &	constValueAtIndex (const int ix, const int iy) const
	value at position defined by a pair of integer coordinates More...

const float &	constValueAtIndex (const int index) const
	value at position defined by the index within the grid More...

float &	valueAt (const QPointF &posf)
	value at position defined by metric coordinates (QPointF) More...

float &	valueAt (const float x, const float y)
	value at position defined by metric coordinates (x,y) More...

const float &	constValueAt (const QPointF &posf) const
	value at position defined by metric coordinates (QPointF) More...

const float &	constValueAt (const float x, const float y) const
	value at position defined by metric coordinates (x,y) More...

bool	coordValid (const float x, const float y) const

bool	coordValid (const QPointF &pos) const

QPoint	indexAt (const QPointF &pos) const
	get index of value at position pos (metric) More...

QPoint	indexOf (const int index) const
	get index (x/y) of the (linear) index 'index' (0..count-1) More...

QPoint	indexOf (const float *element) const
	retrieve index (x/y) of the pointer element. returns -1/-1 if element is not valid. More...

bool	isIndexValid (const QPoint &pos) const
	return true, if position is within the grid More...

bool	isIndexValid (const int x, const int y) const
	return true, if index is within the grid More...

int	index2 (int idx) const
	returns the index of an aligned grid (with the same size and matching origin) with the double cell size (e.g. to scale from a 10m grid to a 20m grid) More...

int	index5 (int idx) const
	returns the index of an aligned grid (the same size) with the 5 times bigger cells (e.g. to scale from a 2m grid to a 10m grid) More...

int	index10 (int idx) const
	returns the index of an aligned grid (the same size) with the 10 times bigger cells (e.g. to scale from a 2m grid to a 20m grid) More...

void	validate (QPoint &pos) const
	force More...

QPointF	cellCenterPoint (const QPoint &pos) const
	get the (metric) centerpoint of cell with index `pos` More...

QPointF	cellCenterPoint (const int &index) const
	get the metric cell center point of the cell given by index 'index' More...

QPointF	cellCenterPoint (float *ptr)
	get the metric cell center point of the cell given py the pointer More...

QRectF	cellRect (const QPoint &pos) const
	get the metric rectangle of the cell with index @pos More...

float *	begin () const
	get "iterator" pointer More...

float *	end () const
	get iterator end-pointer More...

float	max () const
	retrieve the maximum value of a grid More...

float	min () const
	retrieve the minimum value of a grid More...

float	sum () const
	retrieve the sum of the grid More...

float	avg () const
	retrieve the average value of a grid More...

void	add (const float &summand)

void	multiply (const float &factor)

void	limit (const float min_value, const float max_value)
	limit each cell value to (including) min_value and (including) max_value More...

Grid< float >	averaged (const int factor, const int offsetx=0, const int offsety=0) const
	creates a grid with lower resolution and averaged cell values. More...

Grid< float >	normalized (const float targetvalue) const
	normalized returns a normalized grid, in a way that the sum() = More...

float *	ptr (int x, int y)
	get a pointer to the element indexed by "x" and "y" More...

double	distance (const QPoint &p1, const QPoint &p2)
	distance (metric) between p1 and p2 More...

const QPoint	randomPosition () const
	returns a (valid) random position within the grid More...

int	floodFill (QPoint start, float old_color, float color, int max_fill=-1)
	applies a flood fill algorithm to the grid starting at 'start' fills the contingent area with value 'old_color' with 'color' (or stops when 'max_fill' pixels have been filled) returns the number of filled pixels More...

Detailed Description

DEM is a digital elevation model class.

It uses a float grid internally. slope is calculated in "%", i.e. a value of 1 is 45deg (90deg -> inf)

The aspect angles are defined as follows (like ArcGIS, values in degrees): 0 N 270 W x E 90 S 180

Values for height of -1 indicate "out of scope", "invalid" values

Constructor & Destructor Documentation

◆ DEM()

DEM::DEM ( const QString & fileName )

inline

Member Function Documentation

◆ aspectGrid()

const FloatGrid * DEM::aspectGrid ( ) const

inline

◆ createSlopeGrid()

void DEM::createSlopeGrid ( ) const

◆ direction()

float DEM::direction	(	const float	x,
		const float	y
	)

get the direction of the slope at point (x/y) if the slope at the point is 0, "north" (0) is returned.

◆ elevation() [1/2]

float DEM::elevation	(	const float	x,
		const float	y
	)		const

inline

get the elevation (m) at point (x/y)

◆ elevation() [2/2]

float DEM::elevation ( const QPointF p ) const

inline

◆ loadFromFile()

bool DEM::loadFromFile ( const QString & fileName )

loads a DEM from a ESRI style text file.

internally, the DEM has always a resolution of 10m

◆ orientation() [1/2]

float DEM::orientation	(	const float	x,
		const float	y,
		float &	rslope_angle,
		float &	rslope_aspect
	)

inline

◆ orientation() [2/2]

float DEM::orientation	(	const QPointF &	point,
		float &	rslope_angle,
		float &	rslope_aspect
	)		const

get orientation at specific point (x,y) and height

calculate slope and aspect at a given point.

results are params per reference. returns the height at point (x/y) calculation follows: Burrough, P. A. and McDonell, R.A., 1998.Principles of Geographical Information Systems.(Oxford University Press, New York), p. 190. http://uqu.edu.sa/files2/tiny_mce/plugins/filemanager/files/4280125/Principles%20of%20Geographical%20Information%20Systems.pdf

Parameters

point	metric coordinates of point to derive orientation
rslope_angle	RESULTING (passed by reference) slope angle as percentage (i.e: 1:=45 degrees)
rslope_aspect	RESULTING slope direction in degrees (0: North, 90: east, 180: south, 270: west)

◆ slope()

float DEM::slope	(	const float	x,
		const float	y
	)

◆ slopeGrid()

const FloatGrid * DEM::slopeGrid ( ) const

inline

◆ viewGrid()

const FloatGrid * DEM::viewGrid ( ) const

inline

The documentation for this class was generated from the following files:

C:/dev/iland/src/tools/dem.h
C:/dev/iland/src/tools/dem.cpp

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ DEM()

Member Function Documentation

◆ aspectGrid()

◆ createSlopeGrid()

◆ direction()

◆ elevation() [1/2]

◆ elevation() [2/2]

◆ loadFromFile()

◆ orientation() [1/2]

◆ orientation() [2/2]

◆ slope()

◆ slopeGrid()

◆ viewGrid()