This class can be used to generate a scale which may span multiple ranges of values. A scale consists of a lower boundary, an upper boundary, a vector of major scale ticks and a vector of minor scale ticks which divide it into subintervals. A quick look at the example below will give you an idea of how the auto-scaler works.
The auto-scaler produces "reasonable" major and minor step sizes. For linear scales, the major step size will fit into the pattern , where n is an integer. In logarithmic mode (setOptions()) the step size is measured in *decades* and the major step size will be adjusted to fit the pattern
, where n is a natural number including zero.
The step size can be manipulated indirectly using setMaxMajor(). The layout of the scale can be varied with setOptions().
The auto-scaling algorithm can be partly or completely disabled (even temporarily) if a user-defined scale is desired. This can be done with the setScale() function. It can be switched off again with setAutoScale().
The two adjust() members are used to extend the scale if necessary in order to include another range or array of values. The resulting scale division can be obtained with scaleDiv(). reset() resets the scale to zero.
#include <qwt_autoscl.h> #include <iostream.h> double x1[100]; double x2[200]; double range_min, range_max; QwtAutoScale as; // ... determine x1 and x1, range_min and range_max here ... as.reset(); // clear it as.adjust(range_min, range_max); // include a range as.adjust(x1,100); // include an array as.adjust(x2,200); // include another array for (i=0;i<as.scaleDiv().majCnt(); i++) { cout << "Scale tick " << i << " at " << as.scaleDiv().majMark(i) << "\n"; }
Definition at line 78 of file qwt_autoscl.h.
Public Types | |
enum | { None = 0, IncludeRef = 1, Symmetric = 2, Floating = 4, Logarithmic = 8, Inverted = 16 } |
Public Member Functions | |
QwtAutoScale () | |
~QwtAutoScale () | |
void | setAutoScale () |
bool | autoScale () const |
void | setAutoRebuild (bool) |
bool | autoRebuild () const |
void | changeOptions (int opt, bool tf) |
void | setOptions (int opt) |
bool | option (int opt) const |
int | options () const |
void | setMaxMajor (int n) |
int | maxMajor () const |
void | setMaxMinor (int n) |
int | maxMinor () const |
void | setReference (double r) |
double | reference () const |
void | setMargins (double m1, double m2) |
double | loMargin () const |
double | hiMargin () const |
void | setScale (double xmin, double xmax, double step=0.0) |
const QwtScaleDiv & | scaleDiv () const |
void | adjust (double *arr, int n, int reset=0) |
void | adjust (const QwtArray< double > &x, int reset=0) |
void | adjust (double x1, double x2, int reset=0) |
void | build () |
void | reset () |
Protected Member Functions | |
void | buildLinScale () |
void | buildLogScale () |
void | setRange (double x1, double x2) |
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Ctor. Definition at line 17 of file qwt_autoscl.cpp. |
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Dtor. Definition at line 37 of file qwt_autoscl.cpp. |
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Adjust the scale to include a specified interval. This member function extends the boundaries of the scale and re-calculates the step size if necessary in order to include a specified interval. If the reset parameter has nonzero value, the previous state will be cleared.
References build(). |
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Adjust the scale to include a given array of input values. This member function extends the boundaries of the scale and re-calculates the step size if necessary in order to include all values in the array. If the reset parameter has nonzero value, the previous state will be cleared.
References adjust(). |
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Adjust the scale to include a given array of input values. This member function extends the boundaries of the scale and re-calculates the step size if necessary in order to include all values in the array. If the reset parameter has nonzero value, the previous state will be cleared.
References build(). Referenced by adjust(), and QwtPlot::updateAxes(). |
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Referenced by QwtPlot::axisAutoScale(), and QwtPlot::updateAxes(). |
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Re-build the scale. Definition at line 176 of file qwt_autoscl.cpp. References buildLinScale(), buildLogScale(), and QwtScaleDiv::rebuild(). Referenced by adjust(), changeOptions(), setAutoScale(), setMargins(), setMaxMajor(), setMaxMinor(), setOptions(), setReference(), and setScale(). |
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Build a linear scale. Definition at line 213 of file qwt_autoscl.cpp. References QwtScaleDiv::rebuild(), and setRange(). Referenced by build(). |
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build a logarithmic scale Definition at line 300 of file qwt_autoscl.cpp. References QwtScaleDiv::rebuild(), and setRange(). Referenced by build(). |
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Set or reset specified scale options.
References build(). Referenced by QwtPlot::changeAxisOptions(). |
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Referenced by QwtPlot::axisMargins(). |
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Referenced by QwtPlot::axisMaxMajor(). |
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Referenced by QwtPlot::axisMaxMinor(). |
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Returns TRUE if the specified option is set.
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Referenced by QwtPlot::axisOptions(). |
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Referenced by QwtPlot::axisReference(). |
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Set the interval boundaries to zero and clear the scale division. This member function resets an AutoScale object to its initial state. It is needed to clean up the scale before or after subsequent adjust() calls. The boundaries of the scale are set to zero and the scale division is cleared.
References QwtScaleDiv::reset(). Referenced by QwtPlot::updateAxes(). |
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The scale division consists of two boundary values, an array of major tickmarks and an array of minor tickmarks.
Referenced by QwtPlot::axisScale(), QwtPlot::canvasMap(), and QwtPlot::print(). |
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If true, rebuild scale automatically with call to 'adjust'
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Enable auto-scaling. This function is used to switch back to auto-scaling mode if the scale has been frozen temporarily (see setScale()). When auto-scaling is reactivated, the scale will be rebuild, which means that
References build(). Referenced by QwtPlot::setAxisAutoScale(). |
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Specify margins at the scale's endpoints.
References build(). Referenced by QwtPlot::setAxisMargins(). |
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Specify the maximum number of major intervals.
References build(). Referenced by QwtPlot::setAxisMaxMajor(). |
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Specify the maximum number of minor subdivisions within major scale intervals.
References build(). Referenced by QwtPlot::setAxisMaxMinor(). |
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Reset scale options and set specified options.
References build(). Referenced by QwtPlot::setAxisOptions(). |
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Specify a user-defined range.
References LOG_MAX, and LOG_MIN. Referenced by buildLinScale(), buildLogScale(), and setScale(). |
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Specify a reference point.
References build(), LOG_MAX, and LOG_MIN. Referenced by QwtPlot::setAxisReference(). |
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Specify a user-defined scale and switch off auto-scaling.
The fixed-scale mode can switched off using setAutoScale(), which restores the previous values.
References build(), and setRange(). Referenced by QwtPlot::setAxisScale(). |