qwt__scale__engine_8cpp-source.html

QWT5.01用于Qt开发的二维图形库程序

<a name="l00751"></a>00751     <span class="keywordflow">if</span> ( maxMinSteps &gt; 0 )
<a name="l00752"></a>00752     {
<a name="l00753"></a>00753         ticks[QwtScaleDiv::MinorTick] = buildMinorTicks(
<a name="l00754"></a>00754             ticks[QwtScaleDiv::MajorTick], maxMinSteps, stepSize);
<a name="l00755"></a>00755     }
<a name="l00756"></a>00756     
<a name="l00757"></a>00757     <span class="keywordflow">for</span> ( <span class="keywordtype">int</span> i = 0; i &lt; QwtScaleDiv::NTickTypes; i++ )
<a name="l00758"></a>00758         ticks[i] = <a class="code" href="class_qwt_scale_engine.html#f4522cd83e7885f19d35579d42fbc1fc">strip</a>(ticks[i], interval);
<a name="l00759"></a>00759 }
<a name="l00760"></a>00760 
<a name="l00761"></a>00761 QwtValueList QwtLog10ScaleEngine::buildMajorTicks(
<a name="l00762"></a>00762     <span class="keyword">const</span> <a class="code" href="class_qwt_double_interval.html">QwtDoubleInterval</a> &amp;interval, <span class="keywordtype">double</span> stepSize)<span class="keyword"> const</span>
<a name="l00763"></a>00763 <span class="keyword"></span>{
<a name="l00764"></a>00764     <span class="keywordtype">double</span> width = <a class="code" href="class_qwt_log10_scale_engine.html#1d3abcbe5ce63d7f9cfa5a04c028bf55">log10</a>(interval).<a class="code" href="class_qwt_double_interval.html#b5d610e0d1fc9a5a3bc020dd39326327">width</a>();
<a name="l00765"></a>00765 
<a name="l00766"></a>00766     <span class="keywordtype">int</span> numTicks = qRound(width / stepSize) + 1;
<a name="l00767"></a>00767     <span class="keywordflow">if</span> ( numTicks &gt; 10000 )
<a name="l00768"></a>00768         numTicks = 10000;
<a name="l00769"></a>00769 
<a name="l00770"></a>00770     <span class="keyword">const</span> <span class="keywordtype">double</span> lxmin = log(interval.minValue());
<a name="l00771"></a>00771     <span class="keyword">const</span> <span class="keywordtype">double</span> lxmax = log(interval.maxValue());
<a name="l00772"></a>00772     <span class="keyword">const</span> <span class="keywordtype">double</span> lstep = (lxmax - lxmin) / <span class="keywordtype">double</span>(numTicks - 1);
<a name="l00773"></a>00773 
<a name="l00774"></a>00774     QwtValueList ticks;
<a name="l00775"></a>00775 
<a name="l00776"></a>00776     ticks += interval.minValue();
<a name="l00777"></a>00777 
<a name="l00778"></a>00778     <span class="keywordflow">for</span> (<span class="keywordtype">int</span> i = 1; i &lt; numTicks; i++)
<a name="l00779"></a>00779        ticks += exp(lxmin + <span class="keywordtype">double</span>(i) * lstep);
<a name="l00780"></a>00780 
<a name="l00781"></a>00781     ticks += interval.maxValue();
<a name="l00782"></a>00782 
<a name="l00783"></a>00783     <span class="keywordflow">return</span> ticks;
<a name="l00784"></a>00784 }
<a name="l00785"></a>00785 
<a name="l00786"></a>00786 QwtValueList QwtLog10ScaleEngine::buildMinorTicks(
<a name="l00787"></a>00787     <span class="keyword">const</span> QwtValueList &amp;majorTicks, 
<a name="l00788"></a>00788     <span class="keywordtype">int</span> maxMinSteps, <span class="keywordtype">double</span> stepSize)<span class="keyword"> const</span>
<a name="l00789"></a>00789 <span class="keyword"></span>{   
<a name="l00790"></a>00790     <span class="keywordflow">if</span> (stepSize &lt; 1.1)            <span class="comment">// major step width is one decade</span>
<a name="l00791"></a>00791     {
<a name="l00792"></a>00792         <span class="keywordflow">if</span> ( maxMinSteps &lt; 1 )
<a name="l00793"></a>00793             <span class="keywordflow">return</span> QwtValueList();
<a name="l00794"></a>00794             
<a name="l00795"></a>00795         <span class="keywordtype">int</span> k0, kstep, kmax;
<a name="l00796"></a>00796         
<a name="l00797"></a>00797         <span class="keywordflow">if</span> (maxMinSteps &gt;= 8)
<a name="l00798"></a>00798         {
<a name="l00799"></a>00799             k0 = 2;
<a name="l00800"></a>00800             kmax = 9;
<a name="l00801"></a>00801             kstep = 1;
<a name="l00802"></a>00802         }   
<a name="l00803"></a>00803         <span class="keywordflow">else</span> <span class="keywordflow">if</span> (maxMinSteps &gt;= 4)
<a name="l00804"></a>00804         {
<a name="l00805"></a>00805             k0 = 2;
<a name="l00806"></a>00806             kmax = 8;
<a name="l00807"></a>00807             kstep = 2;
<a name="l00808"></a>00808         }   
<a name="l00809"></a>00809         <span class="keywordflow">else</span> <span class="keywordflow">if</span> (maxMinSteps &gt;= 2)
<a name="l00810"></a>00810         {
<a name="l00811"></a>00811             k0 = 2;
<a name="l00812"></a>00812             kmax = 5;
<a name="l00813"></a>00813             kstep = 3;
<a name="l00814"></a>00814         }
<a name="l00815"></a>00815         <span class="keywordflow">else</span>
<a name="l00816"></a>00816         {
<a name="l00817"></a>00817             k0 = 5;
<a name="l00818"></a>00818             kmax = 5;
<a name="l00819"></a>00819             kstep = 1;
<a name="l00820"></a>00820         }
<a name="l00821"></a>00821 
<a name="l00822"></a>00822         QwtValueList minorTicks;
<a name="l00823"></a>00823 
<a name="l00824"></a>00824         <span class="keywordflow">for</span> (<span class="keywordtype">int</span> i = 0; i &lt; (int)majorTicks.count(); i++)
<a name="l00825"></a>00825         {
<a name="l00826"></a>00826             <span class="keyword">const</span> <span class="keywordtype">double</span> v = majorTicks[i];
<a name="l00827"></a>00827             <span class="keywordflow">for</span> (<span class="keywordtype">int</span> k = k0; k&lt;= kmax; k+=kstep)
<a name="l00828"></a>00828                 minorTicks += v * <span class="keywordtype">double</span>(k);
<a name="l00829"></a>00829         }
<a name="l00830"></a>00830 
<a name="l00831"></a>00831         <span class="keywordflow">return</span> minorTicks;
<a name="l00832"></a>00832     }
<a name="l00833"></a>00833     <span class="keywordflow">else</span>  <span class="comment">// major step &gt; one decade</span>
<a name="l00834"></a>00834     {
<a name="l00835"></a>00835         <span class="keywordtype">double</span> minStep = divideInterval(stepSize, maxMinSteps);
<a name="l00836"></a>00836         <span class="keywordflow">if</span> ( minStep == 0.0 )
<a name="l00837"></a>00837             <span class="keywordflow">return</span> QwtValueList();
<a name="l00838"></a>00838 
<a name="l00839"></a>00839         <span class="keywordflow">if</span> ( minStep &lt; 1.0 )
<a name="l00840"></a>00840             minStep = 1.0;
<a name="l00841"></a>00841 
<a name="l00842"></a>00842         <span class="comment">// # subticks per interval</span>
<a name="l00843"></a>00843         <span class="keywordtype">int</span> nMin = qRound(stepSize / minStep) - 1;
<a name="l00844"></a>00844 
<a name="l00845"></a>00845         <span class="comment">// Do the minor steps fit into the interval?</span>
<a name="l00846"></a>00846 
<a name="l00847"></a>00847         <span class="keywordflow">if</span> ( <a class="code" href="class_qwt_scale_arithmetic.html#6c6f982022550fba9ccee034f87461ce">QwtScaleArithmetic::compareEps</a>((nMin +  1) * minStep, 
<a name="l00848"></a>00848             qwtAbs(stepSize), stepSize) &gt; 0)
<a name="l00849"></a>00849         {
<a name="l00850"></a>00850             nMin = 0;
<a name="l00851"></a>00851         }
<a name="l00852"></a>00852 
<a name="l00853"></a>00853         <span class="keywordflow">if</span> (nMin &lt; 1)
<a name="l00854"></a>00854             <span class="keywordflow">return</span> QwtValueList();      <span class="comment">// no subticks</span>
<a name="l00855"></a>00855 
<a name="l00856"></a>00856         <span class="comment">// substep factor = 10^substeps</span>
<a name="l00857"></a>00857         <span class="keyword">const</span> <span class="keywordtype">double</span> minFactor = qwtMax(pow(10.0, minStep), 10.0);
<a name="l00858"></a>00858 
<a name="l00859"></a>00859         QwtValueList minorTicks;
<a name="l00860"></a>00860         <span class="keywordflow">for</span> (<span class="keywordtype">int</span> i = 0; i &lt; (int)majorTicks.count(); i++)
<a name="l00861"></a>00861         {
<a name="l00862"></a>00862             <span class="keywordtype">double</span> val = majorTicks[i];
<a name="l00863"></a>00863             <span class="keywordflow">for</span> (<span class="keywordtype">int</span> k=0; k&lt; nMin; k++)
<a name="l00864"></a>00864             {
<a name="l00865"></a>00865                 val *= minFactor;
<a name="l00866"></a>00866                 minorTicks += val;
<a name="l00867"></a>00867             }
<a name="l00868"></a>00868         }
<a name="l00869"></a>00869         <span class="keywordflow">return</span> minorTicks;
<a name="l00870"></a>00870     }
<a name="l00871"></a>00871 }
<a name="l00872"></a>00872 
<a name="l00884"></a>00884 <a class="code" href="class_qwt_double_interval.html">QwtDoubleInterval</a> QwtLog10ScaleEngine::align(
<a name="l00885"></a>00885     <span class="keyword">const</span> <a class="code" href="class_qwt_double_interval.html">QwtDoubleInterval</a> &amp;interval, <span class="keywordtype">double</span> stepSize)<span class="keyword"> const</span>
<a name="l00886"></a>00886 <span class="keyword"></span>{
<a name="l00887"></a>00887     <span class="keyword">const</span> <a class="code" href="class_qwt_double_interval.html">QwtDoubleInterval</a> intv = <a class="code" href="class_qwt_log10_scale_engine.html#1d3abcbe5ce63d7f9cfa5a04c028bf55">log10</a>(interval);
<a name="l00888"></a>00888 
<a name="l00889"></a>00889     <span class="keyword">const</span> <span class="keywordtype">double</span> x1 = <a class="code" href="class_qwt_scale_arithmetic.html#924d97f2e5db236f43f4d65e430e09c1">QwtScaleArithmetic::floorEps</a>(intv.<a class="code" href="class_qwt_double_interval.html#2d7d56e81ee75911f176c94f6aaf4b8b">minValue</a>(), stepSize);
<a name="l00890"></a>00890     <span class="keyword">const</span> <span class="keywordtype">double</span> x2 = <a class="code" href="class_qwt_scale_arithmetic.html#86da4fc0928457d03201d8b520d7d816">QwtScaleArithmetic::ceilEps</a>(intv.<a class="code" href="class_qwt_double_interval.html#8fd8629d76f24d5494e59458cd79c4e2">maxValue</a>(), stepSize);
<a name="l00891"></a>00891 
<a name="l00892"></a>00892     <span class="keywordflow">return</span> <a class="code" href="class_qwt_log10_scale_engine.html#f08b0486afd765554702f4c237302985">pow10</a>(<a class="code" href="class_qwt_double_interval.html">QwtDoubleInterval</a>(x1, x2));
<a name="l00893"></a>00893 }
<a name="l00894"></a>00894 
<a name="l00899"></a><a class="code" href="class_qwt_log10_scale_engine.html#1d3