NAME¶

QwtMatrixRasterData - A class representing a matrix of values as raster data.

SYNOPSIS¶

#include <qwt_matrix_raster_data.h> Inherits QwtRasterData.

Public Types¶

enum ResampleMode { NearestNeighbour, BilinearInterpolation }

Public Member Functions¶

QwtMatrixRasterData () virtual ~QwtMatrixRasterData () void setResampleMode (ResampleMode mode) ResampleMode resampleMode () const virtual void setInterval (Qt::Axis, const QwtInterval &) void setValueMatrix (const QVector< double > &values, size_t numColumns) const QVector< double > valueMatrix () const size_t numColumns () const size_t numRows () const virtual QRectF pixelHint (const QRectF &) const virtual double value (double x, double y) 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.

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,

Constructor & Destructor Documentation¶

QwtMatrixRasterData::QwtMatrixRasterData ()¶

Constructor.

QwtMatrixRasterData::~QwtMatrixRasterData () [virtual]¶

Destructor.

Member Function Documentation¶

size_t QwtMatrixRasterData::numColumns () const Returns:¶

See also:

size_t QwtMatrixRasterData::numRows () const Returns:¶

See also:

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

Pixel hint. .IP "•" 2 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: Reimplemented from QwtRasterData.

QwtMatrixRasterData::ResampleMode QwtMatrixRasterData::resampleMode () const Returns:¶

See also:

void QwtMatrixRasterData::setInterval (Qt::Axisaxis, 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: See also: Reimplemented from QwtRasterData.

void QwtMatrixRasterData::setResampleMode ( ResampleModemode)¶

Set the resampling algorithm. Parameters: See also:

void QwtMatrixRasterData::setValueMatrix (const QVector< double > &values, size_tnumColumns)¶

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: See also:

double QwtMatrixRasterData::value (doublex, doubley) const [virtual] Returns:¶

Parameters: See also: Implements QwtRasterData.

const QVector< double > QwtMatrixRasterData::valueMatrix () const Returns:¶

See also:

Author¶

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