qwtdata.3

linux下qt的第三方的一个类

.TH "QwtData" 3 "16 Nov 2004" "Version 4.2.0" "Qwt User's Guide" \" -*- nroff -*-
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.SH NAME
QwtData \- 
.SH SYNOPSIS
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.PP
Inherited by \fBQwtArrayData\fP, \fBQwtCPointerData\fP, and \fBQwtDoublePointData\fP.
.PP
.SH "Detailed Description"
.PP 
QwtData defines an interface to any type of data. 

Classes, derived from QwtData may:
.IP "\(bu" 2
store the data in almost any type of container
.IP "\(bu" 2
calculate the data on the fly instead of storing it
.IP "\(bu" 2
implement data with error bars (this implies subclassing \fBQwtPlot\fP, \fBQwtCurve\fP and \fBQwtPlotCurve\fP)
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\fBWarning:\fP
.RS 4
In the future, 'almost any type of container' may be limited to containers supporting bi-directional iterators like the vector, array and list classes in Qt or in the standard template library. 
.RE
.PP

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Definition at line 40 of file qwt_data.h.
.SS "Public Member Functions"

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.RI "virtual \fBQwtData\fP * \fBcopy\fP () const =0"
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.RI "virtual size_t \fBsize\fP () const =0"
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.RI "virtual double \fBx\fP (size_t i) const =0"
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.RI "virtual double \fBy\fP (size_t i) const =0"
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.RI "virtual \fBQwtDoubleRect\fP \fBboundingRect\fP () const"
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.SS "Protected Member Functions"

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.RI "\fBQwtData\fP & \fBoperator=\fP (const \fBQwtData\fP &)"
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.SH "Member Function Documentation"
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.SS "\fBQwtDoubleRect\fP QwtData::boundingRect () const\fC [virtual]\fP"
.PP
Returns the bounding rectangle of the data. If there is no bounding rect, like for empty data the rectangle is invalid: \fBQwtDoubleRect::isValid()\fP == FALSE
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\fBWarning:\fP
.RS 4
This is an slow implementation iterating over all points. It is intended to be overloaded by derived classes. In case of auto scaling \fBboundingRect()\fP is called for every replot, so it might be worth to implement a cache, or use x(0), x(\fBsize()\fP - 1) for ordered data ... 
.RE
.PP

.PP
Reimplemented in \fBQwtArrayData\fP, and \fBQwtCPointerData\fP.
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Definition at line 33 of file qwt_data.cpp.
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References size(), x(), and y().
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Referenced by QwtCurve::boundingRect().
.SS "virtual \fBQwtData\fP* QwtData::copy () const\fC [pure virtual]\fP"
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Return a pointer to a copy (virtual copy constructor) 
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Implemented in \fBQwtDoublePointData\fP, \fBQwtArrayData\fP, and \fBQwtCPointerData\fP.
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Referenced by QwtCurve::copy(), and QwtCurve::setData().
.SS "\fBQwtData\fP& QwtData::operator= (const \fBQwtData\fP &)\fC [protected]\fP"
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Assignment operator (virtualized) 
.SS "virtual size_t QwtData::size () const\fC [pure virtual]\fP"
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Return the size of the data set 
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Implemented in \fBQwtDoublePointData\fP, \fBQwtArrayData\fP, and \fBQwtCPointerData\fP.
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Referenced by boundingRect(), and QwtCurve::dataSize().
.SS "virtual double QwtData::x (size_t i) const\fC [pure virtual]\fP"
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Return the x value of data point i 
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\fBParameters:\fP
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\fIi\fP Index 
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\fBReturns:\fP
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x X value of data point i 
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Implemented in \fBQwtDoublePointData\fP, \fBQwtArrayData\fP, and \fBQwtCPointerData\fP.
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Referenced by boundingRect().
.SS "virtual double QwtData::y (size_t i) const\fC [pure virtual]\fP"
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Return the y value of data point i 
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\fBParameters:\fP
.RS 4
\fIi\fP Index 
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\fBReturns:\fP
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y Y value of data point i 
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Implemented in \fBQwtDoublePointData\fP, \fBQwtArrayData\fP, and \fBQwtCPointerData\fP.
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Referenced by boundingRect(), and QwtCurve::y().

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