.TH "QwtMatrixRasterData" 3 "Mon Dec 28 2020" "Version 6.1.6" "Qwt User's Guide" \" -*- nroff -*- .ad l .nh .SH NAME QwtMatrixRasterData \- A class representing a matrix of values as raster data\&. .SH SYNOPSIS .br .PP .PP \fC#include \fP .PP Inherits \fBQwtRasterData\fP\&. .SS "Public Types" .in +1c .ti -1c .RI "enum \fBResampleMode\fP { \fBNearestNeighbour\fP, \fBBilinearInterpolation\fP }" .br .RI "Resampling algorithm The default setting is NearestNeighbour;\&. " .in -1c .SS "Public Member Functions" .in +1c .ti -1c .RI "\fBQwtMatrixRasterData\fP ()" .br .RI "Constructor\&. " .ti -1c .RI "virtual \fB~QwtMatrixRasterData\fP ()" .br .RI "Destructor\&. " .ti -1c .RI "void \fBsetResampleMode\fP (\fBResampleMode\fP mode)" .br .RI "Set the resampling algorithm\&. " .ti -1c .RI "\fBResampleMode\fP \fBresampleMode\fP () const" .br .ti -1c .RI "virtual void \fBsetInterval\fP (Qt::Axis, const \fBQwtInterval\fP &)" .br .RI "Assign the bounding interval for an axis\&. " .ti -1c .RI "void \fBsetValueMatrix\fP (const QVector< double > &values, int \fBnumColumns\fP)" .br .RI "Assign a value matrix\&. " .ti -1c .RI "const QVector< double > \fBvalueMatrix\fP () const" .br .ti -1c .RI "void \fBsetValue\fP (int row, int col, double \fBvalue\fP)" .br .RI "Change a single value in the matrix\&. " .ti -1c .RI "int \fBnumColumns\fP () const" .br .ti -1c .RI "int \fBnumRows\fP () const" .br .ti -1c .RI "virtual QRectF \fBpixelHint\fP (const QRectF &) const" .br .RI "Calculate the pixel hint\&. " .ti -1c .RI "virtual double \fBvalue\fP (double x, double y) const" .br .in -1c .SH "Detailed Description" .PP A class representing a matrix of values as raster data\&. \fBQwtMatrixRasterData\fP implements an interface for a matrix of equidistant values, that can be used by a \fBQwtPlotRasterItem\fP\&. It implements a couple of resampling algorithms, to provide values for positions, that or not on the value matrix\&. .SH "Member Enumeration Documentation" .PP .SS "enum \fBQwtMatrixRasterData::ResampleMode\fP" .PP Resampling algorithm The default setting is NearestNeighbour;\&. .PP \fBEnumerator\fP .in +1c .TP \fB\fINearestNeighbour \fP\fP Return the value from the matrix, that is nearest to the the requested position\&. .TP \fB\fIBilinearInterpolation \fP\fP Interpolate the value from the distances and values of the 4 surrounding values in the matrix, .SH "Member Function Documentation" .PP .SS "int QwtMatrixRasterData::numColumns () const" .PP \fBReturns\fP .RS 4 Number of columns of the value matrix .RE .PP \fBSee also\fP .RS 4 \fBvalueMatrix()\fP, \fBnumRows()\fP, \fBsetValueMatrix()\fP .RE .PP .SS "int QwtMatrixRasterData::numRows () const" .PP \fBReturns\fP .RS 4 Number of rows of the value matrix .RE .PP \fBSee also\fP .RS 4 \fBvalueMatrix()\fP, \fBnumColumns()\fP, \fBsetValueMatrix()\fP .RE .PP .SS "QRectF QwtMatrixRasterData::pixelHint (const QRectF & area) const\fC [virtual]\fP" .PP Calculate the pixel hint\&. \fBpixelHint()\fP 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\&. .PP .IP "\(bu" 2 NearestNeighbour .br \fBpixelHint()\fP returns the surrounding pixel of the top left value in the matrix\&. .IP "\(bu" 2 BilinearInterpolation .br Returns an empty rectangle recommending to render in target device ( f\&.e\&. screen ) resolution\&. .PP .PP \fBParameters\fP .RS 4 \fIarea\fP Requested area, ignored .RE .PP \fBReturns\fP .RS 4 Calculated hint .RE .PP \fBSee also\fP .RS 4 \fBResampleMode\fP, setMatrix(), \fBsetInterval()\fP .RE .PP .PP Reimplemented from \fBQwtRasterData\fP\&. .SS "\fBQwtMatrixRasterData::ResampleMode\fP QwtMatrixRasterData::resampleMode () const" .PP \fBReturns\fP .RS 4 resampling algorithm .RE .PP \fBSee also\fP .RS 4 \fBsetResampleMode()\fP, \fBvalue()\fP .RE .PP .SS "void QwtMatrixRasterData::setInterval (Qt::Axis axis, const \fBQwtInterval\fP & interval)\fC [virtual]\fP" .PP 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 \fBQwtPlotSpectrogram\fP 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 ) .PP \fBParameters\fP .RS 4 \fIaxis\fP X, Y or Z axis .br \fIinterval\fP Interval .RE .PP \fBSee also\fP .RS 4 \fBQwtRasterData::interval()\fP, \fBsetValueMatrix()\fP .RE .PP .PP Reimplemented from \fBQwtRasterData\fP\&. .SS "void QwtMatrixRasterData::setResampleMode (\fBResampleMode\fP mode)" .PP Set the resampling algorithm\&. .PP \fBParameters\fP .RS 4 \fImode\fP Resampling mode .RE .PP \fBSee also\fP .RS 4 \fBresampleMode()\fP, \fBvalue()\fP .RE .PP .SS "void QwtMatrixRasterData::setValue (int row, int col, double value)" .PP Change a single value in the matrix\&. .PP \fBParameters\fP .RS 4 \fIrow\fP Row index .br \fIcol\fP Column index .br \fIvalue\fP New value .RE .PP \fBSee also\fP .RS 4 \fBvalue()\fP, \fBsetValueMatrix()\fP .RE .PP .SS "void QwtMatrixRasterData::setValueMatrix (const QVector< double > & values, int numColumns)" .PP 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\&. .PP \fBParameters\fP .RS 4 \fIvalues\fP Vector of values .br \fInumColumns\fP Number of columns .RE .PP \fBSee also\fP .RS 4 \fBvalueMatrix()\fP, \fBnumColumns()\fP, \fBnumRows()\fP, \fBsetInterval()\fP() .RE .PP .SS "double QwtMatrixRasterData::value (double x, double y) const\fC [virtual]\fP" .PP \fBReturns\fP .RS 4 the value at a raster position .RE .PP \fBParameters\fP .RS 4 \fIx\fP X value in plot coordinates .br \fIy\fP Y value in plot coordinates .RE .PP \fBSee also\fP .RS 4 \fBResampleMode\fP .RE .PP .PP Implements \fBQwtRasterData\fP\&. .SS "const QVector< double > QwtMatrixRasterData::valueMatrix () const" .PP \fBReturns\fP .RS 4 Value matrix .RE .PP \fBSee also\fP .RS 4 \fBsetValueMatrix()\fP, \fBnumColumns()\fP, \fBnumRows()\fP, \fBsetInterval()\fP .RE .PP .SH "Author" .PP Generated automatically by Doxygen for Qwt User's Guide from the source code\&.