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QwtMatrixRasterData

A class representing a matrix of values as raster data.

#include <qwt_matrix_raster_data.h>

Inherits QwtRasterData.


enum ResampleMode { NearestNeighbour, BilinearInterpolation }


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

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.

Resampling algorithm The default setting is NearestNeighbour;.

Enumerator:

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

Constructor.

Destructor.

Number of columns of the value matrix

See also:

valueMatrix(), numRows(), setValueMatrix()

Number of rows of the value matrix

See also:

valueMatrix(), numColumns(), setValueMatrix()

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:

ResampleMode, setMatrix(), setInterval()

Reimplemented from QwtRasterData.

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

resampling algorithm

See also:

setResampleMode(), value()

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.

Set the resampling algorithm. Parameters:

mode Resampling mode

See also:

resampleMode(), value()

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()()

the value at a raster position

Parameters:

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

See also:

ResampleMode

Implements QwtRasterData.

Value matrix

See also:

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

Generated automatically by Doxygen for Qwt User's Guide from the source code.