Public Types¶

enum ResampleMode { NearestNeighbour, BilinearInterpolation }
Resampling algorithm The default setting is NearestNeighbour;.

Public Member Functions¶

QwtMatrixRasterData ()
Constructor. virtual ~QwtMatrixRasterData ()
Destructor. void setResampleMode (ResampleMode mode)
Set the resampling algorithm. ResampleMode resampleMode () const
virtual void setInterval (Qt::Axis, const QwtInterval &)
Assign the bounding interval for an axis. 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
Calculate the pixel hint. virtual double value (double x, double y) const

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,

int QwtMatrixRasterData::numColumns () const¶

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int QwtMatrixRasterData::numRows () const¶

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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.

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Reimplemented from QwtRasterData.

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

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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 )

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Reimplemented from QwtRasterData.

void QwtMatrixRasterData::setResampleMode (ResampleMode mode)¶

Set the resampling algorithm.

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

Change a single value in the matrix.

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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.

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

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Implements QwtRasterData.

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

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