logarithmicaxis.html

jfreechart1。0。2的api。

<FONT color="green">406</FONT>        protected double computeLogCeil(double upper) {<a name="line.406"></a>
<FONT color="green">407</FONT>    <a name="line.407"></a>
<FONT color="green">408</FONT>            double logCeil;<a name="line.408"></a>
<FONT color="green">409</FONT>            if (this.allowNegativesFlag) {<a name="line.409"></a>
<FONT color="green">410</FONT>                //negative values are allowed<a name="line.410"></a>
<FONT color="green">411</FONT>                if (upper &gt; 10.0) {<a name="line.411"></a>
<FONT color="green">412</FONT>                    //parameter value is &gt; 10<a name="line.412"></a>
<FONT color="green">413</FONT>                    // The Math.log() function is based on e not 10.<a name="line.413"></a>
<FONT color="green">414</FONT>                    logCeil = Math.log(upper) / LOG10_VALUE;<a name="line.414"></a>
<FONT color="green">415</FONT>                    logCeil = Math.ceil(logCeil);<a name="line.415"></a>
<FONT color="green">416</FONT>                    logCeil = Math.pow(10, logCeil);<a name="line.416"></a>
<FONT color="green">417</FONT>                }<a name="line.417"></a>
<FONT color="green">418</FONT>                else if (upper &lt; -10.0) {<a name="line.418"></a>
<FONT color="green">419</FONT>                    //parameter value is &lt; -10<a name="line.419"></a>
<FONT color="green">420</FONT>                    //calculate log using positive value:<a name="line.420"></a>
<FONT color="green">421</FONT>                    logCeil = Math.log(-upper) / LOG10_VALUE;<a name="line.421"></a>
<FONT color="green">422</FONT>                    //calculate ceil using negative value:<a name="line.422"></a>
<FONT color="green">423</FONT>                    logCeil = Math.ceil(-logCeil);<a name="line.423"></a>
<FONT color="green">424</FONT>                    //calculate power using positive value; then negate<a name="line.424"></a>
<FONT color="green">425</FONT>                    logCeil = -Math.pow(10, -logCeil);<a name="line.425"></a>
<FONT color="green">426</FONT>                }<a name="line.426"></a>
<FONT color="green">427</FONT>                else {<a name="line.427"></a>
<FONT color="green">428</FONT>                   //parameter value is -10 &gt; val &lt; 10<a name="line.428"></a>
<FONT color="green">429</FONT>                   logCeil = Math.ceil(upper);     //use as-is<a name="line.429"></a>
<FONT color="green">430</FONT>                }<a name="line.430"></a>
<FONT color="green">431</FONT>            }<a name="line.431"></a>
<FONT color="green">432</FONT>            else {<a name="line.432"></a>
<FONT color="green">433</FONT>                //negative values not allowed<a name="line.433"></a>
<FONT color="green">434</FONT>                if (upper &gt; 0.0) {<a name="line.434"></a>
<FONT color="green">435</FONT>                    //parameter value is &gt; 0<a name="line.435"></a>
<FONT color="green">436</FONT>                    // The Math.log() function is based on e not 10.<a name="line.436"></a>
<FONT color="green">437</FONT>                    logCeil = Math.log(upper) / LOG10_VALUE;<a name="line.437"></a>
<FONT color="green">438</FONT>                    logCeil = Math.ceil(logCeil);<a name="line.438"></a>
<FONT color="green">439</FONT>                    logCeil = Math.pow(10, logCeil);<a name="line.439"></a>
<FONT color="green">440</FONT>                }<a name="line.440"></a>
<FONT color="green">441</FONT>                else {<a name="line.441"></a>
<FONT color="green">442</FONT>                    //parameter value is &lt;= 0<a name="line.442"></a>
<FONT color="green">443</FONT>                    logCeil = Math.ceil(upper);     //use as-is<a name="line.443"></a>
<FONT color="green">444</FONT>                }<a name="line.444"></a>
<FONT color="green">445</FONT>            }<a name="line.445"></a>
<FONT color="green">446</FONT>            return logCeil;<a name="line.446"></a>
<FONT color="green">447</FONT>        }<a name="line.447"></a>
<FONT color="green">448</FONT>    <a name="line.448"></a>
<FONT color="green">449</FONT>        /**<a name="line.449"></a>
<FONT color="green">450</FONT>         * Rescales the axis to ensure that all data is visible.<a name="line.450"></a>
<FONT color="green">451</FONT>         */<a name="line.451"></a>
<FONT color="green">452</FONT>        public void autoAdjustRange() {<a name="line.452"></a>
<FONT color="green">453</FONT>    <a name="line.453"></a>
<FONT color="green">454</FONT>            Plot plot = getPlot();<a name="line.454"></a>
<FONT color="green">455</FONT>            if (plot == null) {<a name="line.455"></a>
<FONT color="green">456</FONT>                return;  // no plot, no data.<a name="line.456"></a>
<FONT color="green">457</FONT>            }<a name="line.457"></a>
<FONT color="green">458</FONT>    <a name="line.458"></a>
<FONT color="green">459</FONT>            if (plot instanceof ValueAxisPlot) {<a name="line.459"></a>
<FONT color="green">460</FONT>                ValueAxisPlot vap = (ValueAxisPlot) plot;<a name="line.460"></a>
<FONT color="green">461</FONT>    <a name="line.461"></a>
<FONT color="green">462</FONT>                double lower;<a name="line.462"></a>
<FONT color="green">463</FONT>                Range r = vap.getDataRange(this);<a name="line.463"></a>
<FONT color="green">464</FONT>                if (r == null) {<a name="line.464"></a>
<FONT color="green">465</FONT>                       //no real data present<a name="line.465"></a>
<FONT color="green">466</FONT>                    r = new Range(DEFAULT_LOWER_BOUND, DEFAULT_UPPER_BOUND);<a name="line.466"></a>
<FONT color="green">467</FONT>                    lower = r.getLowerBound();    //get lower bound value<a name="line.467"></a>
<FONT color="green">468</FONT>                }<a name="line.468"></a>
<FONT color="green">469</FONT>                else {<a name="line.469"></a>
<FONT color="green">470</FONT>                    //actual data is present<a name="line.470"></a>
<FONT color="green">471</FONT>                    lower = r.getLowerBound();    //get lower bound value<a name="line.471"></a>
<FONT color="green">472</FONT>                    if (this.strictValuesFlag<a name="line.472"></a>
<FONT color="green">473</FONT>                            &amp;&amp; !this.allowNegativesFlag &amp;&amp; lower &lt;= 0.0) {<a name="line.473"></a>
<FONT color="green">474</FONT>                        //strict flag set, allow-negatives not set and values &lt;= 0<a name="line.474"></a>
<FONT color="green">475</FONT>                        throw new RuntimeException(<a name="line.475"></a>
<FONT color="green">476</FONT>                            "Values less than or equal to "<a name="line.476"></a>
<FONT color="green">477</FONT>                            + "zero not allowed with logarithmic axis"<a name="line.477"></a>
<FONT color="green">478</FONT>                        );<a name="line.478"></a>
<FONT color="green">479</FONT>                    }<a name="line.479"></a>
<FONT color="green">480</FONT>                }<a name="line.480"></a>
<FONT color="green">481</FONT>    <a name="line.481"></a>
<FONT color="green">482</FONT>                //apply lower margin by decreasing lower bound:<a name="line.482"></a>
<FONT color="green">483</FONT>                final double lowerMargin;<a name="line.483"></a>
<FONT color="green">484</FONT>                if (lower &gt; 0.0 &amp;&amp; (lowerMargin=getLowerMargin()) &gt; 0.0) {<a name="line.484"></a>
<FONT color="green">485</FONT>                       //lower bound and margin OK; get log10 of lower bound<a name="line.485"></a>
<FONT color="green">486</FONT>                  final double logLower = (Math.log(lower) / LOG10_VALUE);<a name="line.486"></a>
<FONT color="green">487</FONT>                  double logAbs;      //get absolute value of log10 value<a name="line.487"></a>
<FONT color="green">488</FONT>                  if((logAbs=Math.abs(logLower)) &lt; 1.0) {<a name="line.488"></a>
<FONT color="green">489</FONT>                    logAbs = 1.0;     //if less than 1.0 then make it 1.0<a name="line.489"></a>
<FONT color="green">490</FONT>                  }              //subtract out margin and get exponential value:<a name="line.490"></a>
<FONT color="green">491</FONT>                  lower = Math.pow(10, (logLower - (logAbs * lowerMargin)));<a name="line.491"></a>
<FONT color="green">492</FONT>                }<a name="line.492"></a>
<FONT color="green">493</FONT>    <a name="line.493"></a>
<FONT color="green">494</FONT>                //if flag then change to log version of lowest value<a name="line.494"></a>
<FONT color="green">495</FONT>                // to make range begin at a 10^n value:<a name="line.495"></a>
<FONT color="green">496</FONT>               if (this.autoRangeNextLogFlag) {<a name="line.496"></a>
<FONT color="green">497</FONT>                   lower = computeLogFloor(lower);<a name="line.497"></a>
<FONT color="green">498</FONT>               }<a name="line.498"></a>
<FONT color="green">499</FONT>    <a name="line.499"></a>
<FONT color="green">500</FONT>                if (!this.allowNegativesFlag &amp;&amp; lower &gt;= 0.0<a name="line.500"></a>
<FONT color="green">501</FONT>                        &amp;&amp; lower &lt; SMALL_LOG_VALUE) {<a name="line.501"></a>
<FONT color="green">502</FONT>                    //negatives not allowed and lower range bound is zero<a name="line.502"></a>
<FONT color="green">503</FONT>                    lower = r.getLowerBound();    //use data range bound instead<a name="line.503"></a>
<FONT color="green">504</FONT>                }<a name="line.504"></a>
<FONT color="green">505</FONT>    <a name="line.505"></a>
<FONT color="green">506</FONT>                double upper = r.getUpperBound();<a name="line.506"></a>
<FONT color="green">507</FONT>    <a name="line.507"></a>
<FONT color="green">508</FONT>                 //apply upper margin by increasing upper bound:<a name="line.508"></a>
<FONT color="green">509</FONT>                final double upperMargin;<a name="line.509"></a>
<FONT color="green">510</FONT>                if (upper &gt; 0.0 &amp;&amp; (upperMargin=getUpperMargin()) &gt; 0.0) {<a name="line.510"></a>
<FONT color="green">511</FONT>                       //upper bound and margin OK; get log10 of upper bound<a name="line.511"></a>
<FONT color="green">512</FONT>                  final double logUpper = (Math.log(upper) / LOG10_VALUE);<a name="line.512"></a>
<FONT color="green">513</FONT>                  double logAbs;      //get absolute value of log10 value<a name="line.513"></a>
<FONT color="green">514</FONT>                  if((logAbs=Math.abs(logUpper)) &lt; 1.0) {<a name="line.514"></a>
<FONT color="green">515</FONT>                    logAbs = 1.0;     //if less than 1.0 then make it 1.0<a name="line.515"></a>
<FONT color="green">516</FONT>                  }              //add in margin and get exponential value:<a name="line.516"></a>
<FONT color="green">517</FONT>                  upper = Math.pow(10, (logUpper + (logAbs * upperMargin)));<a name="line.517"></a>
<FONT color="green">518</FONT>                }<a name="line.518"></a>
<FONT color="green">519</FONT>    <a name="line.519"></a>
<FONT color="green">520</FONT>                if (!this.allowNegativesFlag &amp;&amp; upper &lt; 1.0 &amp;&amp; upper &gt; 0.0<a name="line.520"></a>
<FONT color="green">521</FONT>                        &amp;&amp; lower &gt; 0.0) {<a name="line.521"></a>
<FONT color="green">522</FONT>                    //negatives not allowed and upper bound between 0 &amp; 1<a name="line.522"></a>
<FONT color="green">523</FONT>                    //round up to nearest significant digit for bound:<a name="line.523"></a>
<FONT color="green">524</FONT>                    //get negative exponent:<a name="line.524"></a>
<FONT color="green">525</FONT>                    double expVal = Math.log(upper) / LOG10_VALUE;<a name="line.525"></a>
<FONT color="green">526</FONT>                    expVal = Math.ceil(-expVal + 0.001); //get positive exponent<a name="line.526"></a>
<FONT color="green">527</FONT>                    expVal = Math.pow(10, expVal);      //create multiplier value<a name="line.527"></a>
<FONT color="green">528</FONT>                    //multiply, round up, and divide for bound value:<a name="line.528"></a>
<FONT color="green">529</FONT>                    upper = (expVal &gt; 0.0) ? Math.ceil(upper * expVal) / expVal<a name="line.529"></a>
<FONT color="green">530</FONT>                        : Math.ceil(upper);<a name="line.530"></a>
<FONT color="green">531</FONT>                }<a name="line.531"></a>
<FONT color="green">532</FONT>                else {<a name="line.532"></a>
<FONT color="green">533</FONT>                    //negatives allowed or upper bound not between 0 &amp; 1<a name="line.533"></a>
<FONT color="green">534</FONT>                    //if flag then change to log version of highest value to<a name="line.534"></a>
<FONT color="green">535</FONT>                    // make range begin at a 10^n value; else use nearest int<a name="line.535"></a>
<FONT color="green">536</FONT>                    upper = (this.autoRangeNextLogFlag) ? computeLogCeil(upper)<a name="line.536"></a>
<FONT color="green">537</FONT>                        : Math.ceil(upper);<a name="line.537"></a>
<FONT color="green">538</FONT>                }<a name="line.538"></a>
<FONT color="green">539</FONT>                // ensure the autorange is at least &lt;minRange&gt; in size...<a name="line.539"></a>
<FONT color="green">540</FONT>                double minRange = getAutoRangeMinimumSize();<a name="line.540"></a>
<FONT color="green">541</FONT>                if (upper - lower &lt; minRange) {<a name="line.541"></a>