A class representing a matrix of values as raster data. More...

#include <qwt_matrix_raster_data.h>

Inheritance diagram for QwtMatrixRasterData:

Classes
class	PrivateData
Public Types
enum	ResampleMode { NearestNeighbour, BilinearInterpolation }
	Resampling algorithm The default setting is NearestNeighbour;. More...
Public Member Functions
QwtInterval	interval (Qt::Axis axis) const
int	numColumns () const
int	numRows () const
virtual QRectF	pixelHint (const QRectF &) const
	Calculate the pixel hint.
	QwtMatrixRasterData ()
	Constructor.
ResampleMode	resampleMode () const
void	setInterval (Qt::Axis, const QwtInterval &)
	Assign the bounding interval for an axis.
void	setResampleMode (ResampleMode mode)
	Set the resampling algorithm.
void	setValue (int row, int col, double value)
	Change a single value in the matrix.
void	setValueMatrix (const QVector< double > &values, int numColumns)
	Assign a value matrix.
virtual double	value (double x, double y) const
const QVector< double >	valueMatrix () const
virtual	~QwtMatrixRasterData ()
	Destructor.
Private Member Functions
void	update ()
Private Attributes
PrivateData *	d_data

Detailed Description

A class representing a matrix of values as raster data.

QwtMatrixRasterData implements an interface for a matrix of equidistant values, that can be used by a QwtPlotRasterItem. It implements a couple of resampling algorithms, to provide values for positions, that or not on the value matrix.

Definition at line 25 of file qwt_matrix_raster_data.h.

Member Enumeration Documentation

enum QwtMatrixRasterData::ResampleMode

Resampling algorithm The default setting is NearestNeighbour;.

Enumerator:

NearestNeighbour	Return the value from the matrix, that is nearest to the the requested position.
BilinearInterpolation	Interpolate the value from the distances and values of the 4 surrounding values in the matrix,

Definition at line 32 of file qwt_matrix_raster_data.h.

Constructor & Destructor Documentation

QwtMatrixRasterData::QwtMatrixRasterData ( )

Constructor.

Definition at line 40 of file qwt_matrix_raster_data.cpp.

QwtMatrixRasterData::~QwtMatrixRasterData ( ) [virtual]

Destructor.

Definition at line 47 of file qwt_matrix_raster_data.cpp.

Member Function Documentation

QwtInterval QwtMatrixRasterData::interval ( Qt::Axis axis ) const [virtual]

Returns:: Bounding interval for an axis

See also:: setInterval

Implements QwtRasterData.

Definition at line 102 of file qwt_matrix_raster_data.cpp.

int QwtMatrixRasterData::numColumns ( ) const

Returns:: Number of columns of the value matrix

See also:: valueMatrix(), numRows(), setValueMatrix()

Definition at line 163 of file qwt_matrix_raster_data.cpp.

int QwtMatrixRasterData::numRows ( ) const

Returns:: Number of rows of the value matrix

See also:: valueMatrix(), numColumns(), setValueMatrix()

Definition at line 172 of file qwt_matrix_raster_data.cpp.

QRectF QwtMatrixRasterData::pixelHint ( const QRectF & area ) const [virtual]

Calculate the pixel hint.

pixelHint() returns the geometry of a pixel, that can be used to calculate the resolution and alignment of the plot item, that is representing the data.

NearestNeighbour
pixelHint() returns the surrounding pixel of the top left value in the matrix.

BilinearInterpolation
Returns an empty rectangle recommending to render in target device ( f.e. screen ) resolution.

Parameters:

area	Requested area, ignored

Returns:: Calculated hint

See also:: ResampleMode, setMatrix(), setInterval()

Reimplemented from QwtRasterData.

Definition at line 197 of file qwt_matrix_raster_data.cpp.

QwtMatrixRasterData::ResampleMode QwtMatrixRasterData::resampleMode ( ) const

Returns:: resampling algorithm

See also:: setResampleMode(), value()

Definition at line 67 of file qwt_matrix_raster_data.cpp.

void QwtMatrixRasterData::setInterval	(	Qt::Axis	axis,
		const QwtInterval &	interval
	)

Assign the bounding interval for an axis.

Setting the bounding intervals for the X/Y axis is mandatory to define the positions for the values of the value matrix. The interval in Z direction defines the possible range for the values in the matrix, what is f.e used by QwtPlotSpectrogram to map values to colors. The Z-interval might be the bounding interval of the values in the matrix, but usually it isn't. ( f.e a interval of 0.0-100.0 for values in percentage )

Parameters:

axis	X, Y or Z axis
interval	Interval

See also:: QwtRasterData::interval(), setValueMatrix()

Definition at line 88 of file qwt_matrix_raster_data.cpp.

void QwtMatrixRasterData::setResampleMode ( ResampleMode mode )

Set the resampling algorithm.

Parameters:

mode	Resampling mode

See also:: resampleMode(), value()

Definition at line 58 of file qwt_matrix_raster_data.cpp.

void QwtMatrixRasterData::setValue	(	int	row,
		int	col,
		double	value
	)

Change a single value in the matrix.

Parameters:

row	Row index
col	Column index
value	New value

See also:: value(), setValueMatrix()

Definition at line 149 of file qwt_matrix_raster_data.cpp.

void QwtMatrixRasterData::setValueMatrix	(	const QVector< double > &	values,
		int	numColumns
	)

Assign a value matrix.

The positions of the values are calculated by dividing the bounding rectangle of the X/Y intervals into equidistant rectangles ( pixels ). Each value corresponds to the center of a pixel.

Parameters: