QwtMatrixRasterData Class Reference

#include <qwt_matrix_raster_data.h>

Inherits QwtRasterData.

List of all members.

Public Types
enum	ConrecFlag {   IgnoreAllVerticesOnLevel = 0x01,   IgnoreOutOfRange = 0x02 }
typedef QFlags< ConrecFlag >	ConrecFlags
typedef QMap< double, QPolygonF >	ContourLines
enum	ResampleMode {   NearestNeighbour,   BilinearInterpolation }
Public Member Functions
virtual ContourLines	contourLines (const QRectF &rect, const QSize &raster, const QList< double > &levels, ConrecFlags) const
virtual void	discardRaster ()
virtual void	initRaster (const QRectF &, const QSize &raster)
const QwtInterval &	interval (Qt::Axis) const
size_t	numColumns () const
size_t	numRows () const
virtual QRectF	pixelHint (const QRectF &) const
	QwtMatrixRasterData ()
ResampleMode	resampleMode () const
virtual void	setInterval (Qt::Axis, const QwtInterval &)
void	setResampleMode (ResampleMode mode)
void	setValueMatrix (const QVector< double > &values, size_t numColumns)
virtual double	value (double x, double y) const
const QVector< double >	valueMatrix () const
virtual	~QwtMatrixRasterData ()

---

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.

---

Member Typedef Documentation

typedef QFlags<ConrecFlag> QwtRasterData::ConrecFlags [inherited]

Flags to modify the contour algorithm.

typedef QMap<double, QPolygonF> QwtRasterData::ContourLines [inherited]

Contour lines.

---

Member Enumeration Documentation

enum QwtRasterData::ConrecFlag [inherited]

Flags to modify the contour algorithm.

Enumerator:

IgnoreAllVerticesOnLevel	Ignore all verices on the same level.
IgnoreOutOfRange	Ignore all values, that are out of range.

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,

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Constructor & Destructor Documentation

QwtMatrixRasterData::QwtMatrixRasterData

(

)

Constructor.

QwtMatrixRasterData::~QwtMatrixRasterData

(

)

[virtual]

Destructor.

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Member Function Documentation

QwtRasterData::ContourLines QwtRasterData::contourLines	(	const QRectF &	rect,
		const QSize &	raster,
		const QList< double > &	levels,
		ConrecFlags	flags
	)		const [virtual, inherited]

Calculate contour lines

An adaption of CONREC, a simple contouring algorithm. http://local.wasp.uwa.edu.au/~pbourke/papers/conrec/

void QwtRasterData::discardRaster

(

)

[virtual, inherited]

Discard a raster.

After the composition of an image QwtPlotSpectrogram calls discardRaster().

The default implementation does nothing, but if data has been loaded in initRaster(), it could deleted now.

See also:

initRaster(), value()

void QwtRasterData::initRaster	(	const QRectF &	area,
		const QSize &	raster
	)		[virtual, inherited]

Initialize a raster.

Before the composition of an image QwtPlotSpectrogram calls initRaster, announcing the area and its resolution that will be requested.

The default implementation does nothing, but for data sets that are stored in files, it might be good idea to reimplement initRaster, where the data is resampled and loaded into memory.

Parameters:

area	Area of the raster
raster	Number of horizontal and vertical pixels

See also:

initRaster(), value()

const QwtInterval & QwtRasterData::interval

(

Qt::Axis

axis

)

const [inline, inherited]

Returns:

Bounding interval for a axis

See also:

setInterval

size_t QwtMatrixRasterData::numColumns

(

)

const

Returns:

Number of columns of the value matrix

See also:

valueMatrix(), numRows(), setValueMatrix()

size_t QwtMatrixRasterData::numRows

(

)

const

Returns:

Number of rows of the value matrix

See also:

valueMatrix(), numColumns(), setValueMatrix()

QRectF QwtMatrixRasterData::pixelHint

(

const QRectF &

)

const [virtual]

Pixel hint.

• 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.

See also:

ResampleMode, setMatrix(), setInterval()

Reimplemented from QwtRasterData.

QwtMatrixRasterData::ResampleMode QwtMatrixRasterData::resampleMode

(

)

const

Returns:

resampling algorithm

See also:

setResampleMode(), value()

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

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()

Reimplemented from QwtRasterData.

void QwtMatrixRasterData::setResampleMode

(

ResampleMode

mode

)

Set the resampling algorithm.

Parameters:

mode	Resampling mode

See also:

resampleMode(), value()

void QwtMatrixRasterData::setValueMatrix	(	const QVector< double > &	values,
		size_t	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:

values	Vector of values
numColumns	Number of columns

See also:

valueMatrix(), numColumns(), numRows(), setInterval()()

double QwtMatrixRasterData::value	(	double	x,
		double	y
	)		const [virtual]

Returns:

the value at a raster position

Parameters:

x	X value in plot coordinates
y	Y value in plot coordinates

See also:

ResampleMode

Implements QwtRasterData.

const QVector< double > QwtMatrixRasterData::valueMatrix

(

)

const

Returns:

Value matrix

See also:

setValueMatrix(), numColumns(), numRows(), setInterval()