datasetutilities.html

jfreechart1。0。2的api。

<FONT color="green">546</FONT>    <a name="line.546"></a>
<FONT color="green">547</FONT>            return true;<a name="line.547"></a>
<FONT color="green">548</FONT>    <a name="line.548"></a>
<FONT color="green">549</FONT>        }<a name="line.549"></a>
<FONT color="green">550</FONT>    <a name="line.550"></a>
<FONT color="green">551</FONT>        /**<a name="line.551"></a>
<FONT color="green">552</FONT>         * Returns &lt;code&gt;true&lt;/code&gt; if the dataset is empty (or &lt;code&gt;null&lt;/code&gt;),<a name="line.552"></a>
<FONT color="green">553</FONT>         * and &lt;code&gt;false&lt;/code&gt; otherwise.<a name="line.553"></a>
<FONT color="green">554</FONT>         *<a name="line.554"></a>
<FONT color="green">555</FONT>         * @param dataset  the dataset (&lt;code&gt;null&lt;/code&gt; permitted).<a name="line.555"></a>
<FONT color="green">556</FONT>         *<a name="line.556"></a>
<FONT color="green">557</FONT>         * @return A boolean.<a name="line.557"></a>
<FONT color="green">558</FONT>         */<a name="line.558"></a>
<FONT color="green">559</FONT>        public static boolean isEmptyOrNull(CategoryDataset dataset) {<a name="line.559"></a>
<FONT color="green">560</FONT>    <a name="line.560"></a>
<FONT color="green">561</FONT>            if (dataset == null) {<a name="line.561"></a>
<FONT color="green">562</FONT>                return true;<a name="line.562"></a>
<FONT color="green">563</FONT>            }<a name="line.563"></a>
<FONT color="green">564</FONT>    <a name="line.564"></a>
<FONT color="green">565</FONT>            int rowCount = dataset.getRowCount();<a name="line.565"></a>
<FONT color="green">566</FONT>            int columnCount = dataset.getColumnCount();<a name="line.566"></a>
<FONT color="green">567</FONT>            if (rowCount == 0 || columnCount == 0) {<a name="line.567"></a>
<FONT color="green">568</FONT>                return true;<a name="line.568"></a>
<FONT color="green">569</FONT>            }<a name="line.569"></a>
<FONT color="green">570</FONT>    <a name="line.570"></a>
<FONT color="green">571</FONT>            for (int r = 0; r &lt; rowCount; r++) {<a name="line.571"></a>
<FONT color="green">572</FONT>                for (int c = 0; c &lt; columnCount; c++) {<a name="line.572"></a>
<FONT color="green">573</FONT>                    if (dataset.getValue(r, c) != null) {<a name="line.573"></a>
<FONT color="green">574</FONT>                        return false;<a name="line.574"></a>
<FONT color="green">575</FONT>                    }<a name="line.575"></a>
<FONT color="green">576</FONT>    <a name="line.576"></a>
<FONT color="green">577</FONT>                }<a name="line.577"></a>
<FONT color="green">578</FONT>            }<a name="line.578"></a>
<FONT color="green">579</FONT>    <a name="line.579"></a>
<FONT color="green">580</FONT>            return true;<a name="line.580"></a>
<FONT color="green">581</FONT>    <a name="line.581"></a>
<FONT color="green">582</FONT>        }<a name="line.582"></a>
<FONT color="green">583</FONT>    <a name="line.583"></a>
<FONT color="green">584</FONT>        /**<a name="line.584"></a>
<FONT color="green">585</FONT>         * Returns &lt;code&gt;true&lt;/code&gt; if the dataset is empty (or &lt;code&gt;null&lt;/code&gt;),<a name="line.585"></a>
<FONT color="green">586</FONT>         * and &lt;code&gt;false&lt;/code&gt; otherwise.<a name="line.586"></a>
<FONT color="green">587</FONT>         *<a name="line.587"></a>
<FONT color="green">588</FONT>         * @param dataset  the dataset (&lt;code&gt;null&lt;/code&gt; permitted).<a name="line.588"></a>
<FONT color="green">589</FONT>         *<a name="line.589"></a>
<FONT color="green">590</FONT>         * @return A boolean.<a name="line.590"></a>
<FONT color="green">591</FONT>         */<a name="line.591"></a>
<FONT color="green">592</FONT>        public static boolean isEmptyOrNull(XYDataset dataset) {<a name="line.592"></a>
<FONT color="green">593</FONT>    <a name="line.593"></a>
<FONT color="green">594</FONT>            boolean result = true;<a name="line.594"></a>
<FONT color="green">595</FONT>    <a name="line.595"></a>
<FONT color="green">596</FONT>            if (dataset != null) {<a name="line.596"></a>
<FONT color="green">597</FONT>                for (int s = 0; s &lt; dataset.getSeriesCount(); s++) {<a name="line.597"></a>
<FONT color="green">598</FONT>                    if (dataset.getItemCount(s) &gt; 0) {<a name="line.598"></a>
<FONT color="green">599</FONT>                        result = false;<a name="line.599"></a>
<FONT color="green">600</FONT>                        continue;<a name="line.600"></a>
<FONT color="green">601</FONT>                    }<a name="line.601"></a>
<FONT color="green">602</FONT>                }<a name="line.602"></a>
<FONT color="green">603</FONT>            }<a name="line.603"></a>
<FONT color="green">604</FONT>    <a name="line.604"></a>
<FONT color="green">605</FONT>            return result;<a name="line.605"></a>
<FONT color="green">606</FONT>    <a name="line.606"></a>
<FONT color="green">607</FONT>        }<a name="line.607"></a>
<FONT color="green">608</FONT>    <a name="line.608"></a>
<FONT color="green">609</FONT>        /**<a name="line.609"></a>
<FONT color="green">610</FONT>         * Returns the range of values in the domain (x-values) of a dataset.<a name="line.610"></a>
<FONT color="green">611</FONT>         *<a name="line.611"></a>
<FONT color="green">612</FONT>         * @param dataset  the dataset (&lt;code&gt;null&lt;/code&gt; not permitted).<a name="line.612"></a>
<FONT color="green">613</FONT>         *<a name="line.613"></a>
<FONT color="green">614</FONT>         * @return The range of values (possibly &lt;code&gt;null&lt;/code&gt;).<a name="line.614"></a>
<FONT color="green">615</FONT>         */<a name="line.615"></a>
<FONT color="green">616</FONT>        public static Range findDomainBounds(XYDataset dataset) {<a name="line.616"></a>
<FONT color="green">617</FONT>            return findDomainBounds(dataset, true);<a name="line.617"></a>
<FONT color="green">618</FONT>        }<a name="line.618"></a>
<FONT color="green">619</FONT>    <a name="line.619"></a>
<FONT color="green">620</FONT>        /**<a name="line.620"></a>
<FONT color="green">621</FONT>         * Returns the range of values in the domain (x-values) of a dataset.<a name="line.621"></a>
<FONT color="green">622</FONT>         *<a name="line.622"></a>
<FONT color="green">623</FONT>         * @param dataset  the dataset (&lt;code&gt;null&lt;/code&gt; not permitted).<a name="line.623"></a>
<FONT color="green">624</FONT>         * @param includeInterval  determines whether or not the x-interval is taken<a name="line.624"></a>
<FONT color="green">625</FONT>         *                         into account (only applies if the dataset is an<a name="line.625"></a>
<FONT color="green">626</FONT>         *                         {@link IntervalXYDataset}).<a name="line.626"></a>
<FONT color="green">627</FONT>         *<a name="line.627"></a>
<FONT color="green">628</FONT>         * @return The range of values (possibly &lt;code&gt;null&lt;/code&gt;).<a name="line.628"></a>
<FONT color="green">629</FONT>         */<a name="line.629"></a>
<FONT color="green">630</FONT>        public static Range findDomainBounds(XYDataset dataset, <a name="line.630"></a>
<FONT color="green">631</FONT>                                             boolean includeInterval) {<a name="line.631"></a>
<FONT color="green">632</FONT>    <a name="line.632"></a>
<FONT color="green">633</FONT>            if (dataset == null) {<a name="line.633"></a>
<FONT color="green">634</FONT>                throw new IllegalArgumentException("Null 'dataset' argument.");<a name="line.634"></a>
<FONT color="green">635</FONT>            }<a name="line.635"></a>
<FONT color="green">636</FONT>    <a name="line.636"></a>
<FONT color="green">637</FONT>            Range result = null;<a name="line.637"></a>
<FONT color="green">638</FONT>            // if the dataset implements DomainInfo, life is easier<a name="line.638"></a>
<FONT color="green">639</FONT>            if (dataset instanceof DomainInfo) {<a name="line.639"></a>
<FONT color="green">640</FONT>                DomainInfo info = (DomainInfo) dataset;<a name="line.640"></a>
<FONT color="green">641</FONT>                result = info.getDomainBounds(includeInterval);<a name="line.641"></a>
<FONT color="green">642</FONT>            }<a name="line.642"></a>
<FONT color="green">643</FONT>            else {<a name="line.643"></a>
<FONT color="green">644</FONT>                result = iterateDomainBounds(dataset, includeInterval);<a name="line.644"></a>
<FONT color="green">645</FONT>            }<a name="line.645"></a>
<FONT color="green">646</FONT>            return result;<a name="line.646"></a>
<FONT color="green">647</FONT>            <a name="line.647"></a>
<FONT color="green">648</FONT>        }<a name="line.648"></a>
<FONT color="green">649</FONT>    <a name="line.649"></a>
<FONT color="green">650</FONT>        /**<a name="line.650"></a>
<FONT color="green">651</FONT>         * Iterates over the items in an {@link XYDataset} to find<a name="line.651"></a>
<FONT color="green">652</FONT>         * the range of x-values. <a name="line.652"></a>
<FONT color="green">653</FONT>         *  <a name="line.653"></a>
<FONT color="green">654</FONT>         * @param dataset  the dataset (&lt;code&gt;null&lt;/code&gt; not permitted).<a name="line.654"></a>
<FONT color="green">655</FONT>         * <a name="line.655"></a>
<FONT color="green">656</FONT>         * @return The range (possibly &lt;code&gt;null&lt;/code&gt;).<a name="line.656"></a>
<FONT color="green">657</FONT>         */<a name="line.657"></a>
<FONT color="green">658</FONT>        public static Range iterateDomainBounds(XYDataset dataset) {<a name="line.658"></a>
<FONT color="green">659</FONT>            return iterateDomainBounds(dataset, true);<a name="line.659"></a>
<FONT color="green">660</FONT>        }<a name="line.660"></a>
<FONT color="green">661</FONT>    <a name="line.661"></a>
<FONT color="green">662</FONT>        /**<a name="line.662"></a>
<FONT color="green">663</FONT>         * Iterates over the items in an {@link XYDataset} to find<a name="line.663"></a>
<FONT color="green">664</FONT>         * the range of x-values. <a name="line.664"></a>
<FONT color="green">665</FONT>         *  <a name="line.665"></a>
<FONT color="green">666</FONT>         * @param dataset  the dataset (&lt;code&gt;null&lt;/code&gt; not permitted).<a name="line.666"></a>
<FONT color="green">667</FONT>         * @param includeInterval  a flag that determines, for an IntervalXYDataset,<a name="line.667"></a>
<FONT color="green">668</FONT>         *                         whether the x-interval or just the x-value is <a name="line.668"></a>
<FONT color="green">669</FONT>         *                         used to determine the overall range.<a name="line.669"></a>
<FONT color="green">670</FONT>         *   <a name="line.670"></a>
<FONT color="green">671</FONT>         * @return The range (possibly &lt;code&gt;null&lt;/code&gt;).<a name="line.671"></a>
<FONT color="green">672</FONT>         */<a name="line.672"></a>
<FONT color="green">673</FONT>        public static Range iterateDomainBounds(XYDataset dataset, <a name="line.673"></a>
<FONT color="green">674</FONT>                                                boolean includeInterval) {<a name="line.674"></a>
<FONT color="green">675</FONT>            if (dataset == null) {<a name="line.675"></a>
<FONT color="green">676</FONT>                throw new IllegalArgumentException("Null 'dataset' argument.");   <a name="line.676"></a>
<FONT color="green">677</FONT>            }<a name="line.677"></a>
<FONT color="green">678</FONT>            double minimum = Double.POSITIVE_INFINITY;<a name="line.678"></a>
<FONT color="green">679</FONT>            double maximum = Double.NEGATIVE_INFINITY;<a name="line.679"></a>
<FONT color="green">680</FONT>            int seriesCount = dataset.getSeriesCount();<a name="line.680"></a>
<FONT color="green">681</FONT>            double lvalue;<a name="line.681"></a>
<FONT color="gr