Sources_For_Linux/Qwt/doc/man/man3/QwtMatrixRasterData.3

.TH "QwtMatrixRasterData" 3 "Mon Dec 28 2020" "Version 6.1.6" "Qwt User's Guide" \" -*- nroff -*-
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.SH NAME
QwtMatrixRasterData \- A class representing a matrix of values as raster data\&.  

.SH SYNOPSIS
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.PP
.PP
\fC#include <qwt_matrix_raster_data\&.h>\fP
.PP
Inherits \fBQwtRasterData\fP\&.
.SS "Public Types"

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.ti -1c
.RI "enum \fBResampleMode\fP { \fBNearestNeighbour\fP, \fBBilinearInterpolation\fP }"
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.RI "Resampling algorithm The default setting is NearestNeighbour;\&. "
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.SS "Public Member Functions"

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.RI "\fBQwtMatrixRasterData\fP ()"
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.RI "Constructor\&. "
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.RI "virtual \fB~QwtMatrixRasterData\fP ()"
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.RI "Destructor\&. "
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.RI "void \fBsetResampleMode\fP (\fBResampleMode\fP mode)"
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.RI "Set the resampling algorithm\&. "
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.RI "\fBResampleMode\fP \fBresampleMode\fP () const"
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.RI "virtual void \fBsetInterval\fP (Qt::Axis, const \fBQwtInterval\fP &)"
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.RI "Assign the bounding interval for an axis\&. "
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.RI "void \fBsetValueMatrix\fP (const QVector< double > &values, int \fBnumColumns\fP)"
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.RI "Assign a value matrix\&. "
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.RI "const QVector< double > \fBvalueMatrix\fP () const"
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.RI "void \fBsetValue\fP (int row, int col, double \fBvalue\fP)"
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.RI "Change a single value in the matrix\&. "
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.RI "int \fBnumColumns\fP () const"
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.RI "int \fBnumRows\fP () const"
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.RI "virtual QRectF \fBpixelHint\fP (const QRectF &) const"
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.RI "Calculate the pixel hint\&. "
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.RI "virtual double \fBvalue\fP (double x, double y) const"
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.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
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.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
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 \fBpixelHint()\fP returns the surrounding pixel of the top left value in the matrix\&.
.IP "\(bu" 2
BilinearInterpolation
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 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 
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\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 
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\fIcol\fP Column index 
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\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 
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\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 
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\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\&.