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

#include <qwt_matrix_raster_data.h>

Inheritance diagram for QwtMatrixRasterData:

Public Types
enum	ResampleMode { NearestNeighbour , BilinearInterpolation , BicubicInterpolation }
	Resampling algorithm The default setting is NearestNeighbour;. More...

Public Types inherited from QwtRasterData
enum	Attribute { WithoutGaps = 0x01 }
	Raster data attributes. More...

enum	ConrecFlag { IgnoreAllVerticesOnLevel = 0x01 , IgnoreOutOfRange = 0x02 }
	Flags to modify the contour algorithm. More...

typedef QMap< double, QPolygonF >	ContourLines
	Contour lines.

typedef QFlags< Attribute >	Attributes

typedef QFlags< ConrecFlag >	ConrecFlags

Public Member Functions
	QwtMatrixRasterData ()
	Constructor.

virtual	~QwtMatrixRasterData ()
	Destructor.

void	setResampleMode (ResampleMode mode)
	Set the resampling algorithm.

ResampleMode	resampleMode () const

void	setInterval (Qt::Axis, const QwtInterval &)
	Assign the bounding interval for an axis.

virtual QwtInterval	interval (Qt::Axis axis) const override final

void	setValueMatrix (const QVector< double > &values, int numColumns)
	Assign a value matrix.

const QVector< double >	valueMatrix () const

void	setValue (int row, int col, double value)
	Change a single value in the matrix.

int	numColumns () const

int	numRows () const

virtual QRectF	pixelHint (const QRectF &) const override
	Calculate the pixel hint.

virtual double	value (double x, double y) const override

Public Member Functions inherited from QwtRasterData
	QwtRasterData ()
	Constructor.

virtual	~QwtRasterData ()
	Destructor.

void	setAttribute (Attribute, bool on=true)

bool	testAttribute (Attribute) const

virtual void	initRaster (const QRectF &, const QSize &raster)
	Initialize a raster.

virtual void	discardRaster ()
	Discard a raster.

virtual ContourLines	contourLines (const QRectF &rect, const QSize &raster, const QList< double > &levels, ConrecFlags) const

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 28 of file qwt_matrix_raster_data.h.

Member Enumeration Documentation

◆ ResampleMode

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,
BicubicInterpolation	Interpolate the value from the 16 surrounding values in the matrix using hermite bicubic interpolation

Definition at line 35 of file qwt_matrix_raster_data.h.

Constructor & Destructor Documentation

◆ QwtMatrixRasterData()

QwtMatrixRasterData::QwtMatrixRasterData ( )

Constructor.

Definition at line 72 of file qwt_matrix_raster_data.cpp.

◆ ~QwtMatrixRasterData()

QwtMatrixRasterData::~QwtMatrixRasterData ( )

virtual

Destructor.

Definition at line 79 of file qwt_matrix_raster_data.cpp.

Member Function Documentation

◆ interval()

QwtInterval QwtMatrixRasterData::interval ( Qt::Axis axis ) const

finaloverridevirtual

Returns: Bounding interval for an axis

See also: setInterval

Implements QwtRasterData.

Definition at line 134 of file qwt_matrix_raster_data.cpp.

◆ numColumns()

int QwtMatrixRasterData::numColumns ( ) const

Returns: Number of columns of the value matrix

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

Definition at line 195 of file qwt_matrix_raster_data.cpp.

◆ numRows()

int QwtMatrixRasterData::numRows ( ) const

Returns: Number of rows of the value matrix

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

Definition at line 204 of file qwt_matrix_raster_data.cpp.

◆ pixelHint()

QRectF QwtMatrixRasterData::pixelHint ( const QRectF & area ) const

overridevirtual

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 229 of file qwt_matrix_raster_data.cpp.

◆ resampleMode()

QwtMatrixRasterData::ResampleMode QwtMatrixRasterData::resampleMode ( ) const

Returns: resampling algorithm

See also: setResampleMode(), value()

Definition at line 99 of file qwt_matrix_raster_data.cpp.

◆ setInterval()

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 120 of file qwt_matrix_raster_data.cpp.

◆ setResampleMode()

void QwtMatrixRasterData::setResampleMode ( ResampleMode mode )

Set the resampling algorithm.

Parameters

mode	Resampling mode

See also: resampleMode(), value()

Definition at line 90 of file qwt_matrix_raster_data.cpp.

◆ setValue()

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 181 of file qwt_matrix_raster_data.cpp.

◆ setValueMatrix()

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