QwtMatrixRasterData(3) | Qwt User's Guide | QwtMatrixRasterData(3) |
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, BicubicInterpolation }
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
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
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
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.
Member Function Documentation
QwtInterval QwtMatrixRasterData::interval (Qt::Axis axis) const [final], [override], [virtual]
Returns
See also
Implements QwtRasterData.
Definition at line 134 of file qwt_matrix_raster_data.cpp.
int QwtMatrixRasterData::numColumns () const
Returns
See also
Definition at line 195 of file qwt_matrix_raster_data.cpp.
int QwtMatrixRasterData::numRows () const
Returns
See also
Definition at line 204 of file qwt_matrix_raster_data.cpp.
QRectF QwtMatrixRasterData::pixelHint (const QRectF & area) const [override], [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.
Parameters
Returns
See also
Reimplemented from QwtRasterData.
Definition at line 229 of file qwt_matrix_raster_data.cpp.
QwtMatrixRasterData::ResampleMode QwtMatrixRasterData::resampleMode () const
Returns
See also
Definition at line 99 of file qwt_matrix_raster_data.cpp.
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
interval Interval
See also
Definition at line 120 of file qwt_matrix_raster_data.cpp.
void QwtMatrixRasterData::setResampleMode (ResampleMode mode)
Set the resampling algorithm.
Parameters
See also
Definition at line 90 of file qwt_matrix_raster_data.cpp.
void QwtMatrixRasterData::setValue (int row, int col, double value)
Change a single value in the matrix.
Parameters
col Column index
value New value
See also
Definition at line 181 of file qwt_matrix_raster_data.cpp.
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
numColumns Number of columns
See also
Definition at line 155 of file qwt_matrix_raster_data.cpp.
double QwtMatrixRasterData::value (double x, double y) const [override], [virtual]
Returns
Parameters
y Y value in plot coordinates
See also
Implements QwtRasterData.
Definition at line 256 of file qwt_matrix_raster_data.cpp.
const QVector< double > QwtMatrixRasterData::valueMatrix () const
Returns
See also
Definition at line 167 of file qwt_matrix_raster_data.cpp.
Author
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Sun Jul 18 2021 | Version 6.2.0 |