movingaverage.html

jfreechart1。0。2的api。

<FONT color="green">151</FONT>                    long serial = period.getSerialIndex();<a name="line.151"></a>
<FONT color="green">152</FONT>    <a name="line.152"></a>
<FONT color="green">153</FONT>                    if (serial &gt;= firstSerial) {<a name="line.153"></a>
<FONT color="green">154</FONT>                        // work out the average for the earlier values...<a name="line.154"></a>
<FONT color="green">155</FONT>                        int n = 0;<a name="line.155"></a>
<FONT color="green">156</FONT>                        double sum = 0.0;<a name="line.156"></a>
<FONT color="green">157</FONT>                        long serialLimit = period.getSerialIndex() - periodCount;<a name="line.157"></a>
<FONT color="green">158</FONT>                        int offset = 0;<a name="line.158"></a>
<FONT color="green">159</FONT>                        boolean finished = false;<a name="line.159"></a>
<FONT color="green">160</FONT>    <a name="line.160"></a>
<FONT color="green">161</FONT>                        while ((offset &lt; periodCount) &amp;&amp; (!finished)) {<a name="line.161"></a>
<FONT color="green">162</FONT>                            if ((i - offset) &gt;= 0) {<a name="line.162"></a>
<FONT color="green">163</FONT>                                TimeSeriesDataItem item <a name="line.163"></a>
<FONT color="green">164</FONT>                                    = source.getDataItem(i - offset);<a name="line.164"></a>
<FONT color="green">165</FONT>                                RegularTimePeriod p = item.getPeriod();<a name="line.165"></a>
<FONT color="green">166</FONT>                                Number v = item.getValue();<a name="line.166"></a>
<FONT color="green">167</FONT>                                long currentIndex = p.getSerialIndex();<a name="line.167"></a>
<FONT color="green">168</FONT>                                if (currentIndex &gt; serialLimit) {<a name="line.168"></a>
<FONT color="green">169</FONT>                                    if (v != null) {<a name="line.169"></a>
<FONT color="green">170</FONT>                                        sum = sum + v.doubleValue();<a name="line.170"></a>
<FONT color="green">171</FONT>                                        n = n + 1;<a name="line.171"></a>
<FONT color="green">172</FONT>                                    }<a name="line.172"></a>
<FONT color="green">173</FONT>                                }<a name="line.173"></a>
<FONT color="green">174</FONT>                                else {<a name="line.174"></a>
<FONT color="green">175</FONT>                                    finished = true;<a name="line.175"></a>
<FONT color="green">176</FONT>                                }<a name="line.176"></a>
<FONT color="green">177</FONT>                            }<a name="line.177"></a>
<FONT color="green">178</FONT>                            offset = offset + 1;<a name="line.178"></a>
<FONT color="green">179</FONT>                        }<a name="line.179"></a>
<FONT color="green">180</FONT>                        if (n &gt; 0) {<a name="line.180"></a>
<FONT color="green">181</FONT>                            result.add(period, sum / n);<a name="line.181"></a>
<FONT color="green">182</FONT>                        }<a name="line.182"></a>
<FONT color="green">183</FONT>                        else {<a name="line.183"></a>
<FONT color="green">184</FONT>                            result.add(period, null);<a name="line.184"></a>
<FONT color="green">185</FONT>                        }<a name="line.185"></a>
<FONT color="green">186</FONT>                    }<a name="line.186"></a>
<FONT color="green">187</FONT>    <a name="line.187"></a>
<FONT color="green">188</FONT>                }<a name="line.188"></a>
<FONT color="green">189</FONT>            }<a name="line.189"></a>
<FONT color="green">190</FONT>    <a name="line.190"></a>
<FONT color="green">191</FONT>            return result;<a name="line.191"></a>
<FONT color="green">192</FONT>    <a name="line.192"></a>
<FONT color="green">193</FONT>        }<a name="line.193"></a>
<FONT color="green">194</FONT>    <a name="line.194"></a>
<FONT color="green">195</FONT>        /**<a name="line.195"></a>
<FONT color="green">196</FONT>         * Creates a new {@link TimeSeries} containing moving average values for <a name="line.196"></a>
<FONT color="green">197</FONT>         * the given series, calculated by number of points (irrespective of the <a name="line.197"></a>
<FONT color="green">198</FONT>         * 'age' of those points).  If the series is empty (contains zero items), <a name="line.198"></a>
<FONT color="green">199</FONT>         * the result is an empty series.<a name="line.199"></a>
<FONT color="green">200</FONT>         * &lt;p&gt;<a name="line.200"></a>
<FONT color="green">201</FONT>         * Developed by Benoit Xhenseval (www.ObjectLab.co.uk).<a name="line.201"></a>
<FONT color="green">202</FONT>         *<a name="line.202"></a>
<FONT color="green">203</FONT>         * @param source  the source series.<a name="line.203"></a>
<FONT color="green">204</FONT>         * @param name  the name of the new series.<a name="line.204"></a>
<FONT color="green">205</FONT>         * @param pointCount  the number of POINTS used in the average calculation <a name="line.205"></a>
<FONT color="green">206</FONT>         *                    (not periods!)<a name="line.206"></a>
<FONT color="green">207</FONT>         *<a name="line.207"></a>
<FONT color="green">208</FONT>         * @return The moving average series.<a name="line.208"></a>
<FONT color="green">209</FONT>         */<a name="line.209"></a>
<FONT color="green">210</FONT>        public static TimeSeries createPointMovingAverage(TimeSeries source,<a name="line.210"></a>
<FONT color="green">211</FONT>                                                          String name, <a name="line.211"></a>
<FONT color="green">212</FONT>                                                          int pointCount) {<a name="line.212"></a>
<FONT color="green">213</FONT>    <a name="line.213"></a>
<FONT color="green">214</FONT>            // check arguments<a name="line.214"></a>
<FONT color="green">215</FONT>            if (source == null) {<a name="line.215"></a>
<FONT color="green">216</FONT>                throw new IllegalArgumentException("Null 'source'.");<a name="line.216"></a>
<FONT color="green">217</FONT>            }<a name="line.217"></a>
<FONT color="green">218</FONT>    <a name="line.218"></a>
<FONT color="green">219</FONT>            if (pointCount &lt; 2) {<a name="line.219"></a>
<FONT color="green">220</FONT>                throw new IllegalArgumentException(<a name="line.220"></a>
<FONT color="green">221</FONT>                    "periodCount must be greater than or equal to 2."<a name="line.221"></a>
<FONT color="green">222</FONT>                );<a name="line.222"></a>
<FONT color="green">223</FONT>            }<a name="line.223"></a>
<FONT color="green">224</FONT>    <a name="line.224"></a>
<FONT color="green">225</FONT>            TimeSeries result = new TimeSeries(name, source.getTimePeriodClass());<a name="line.225"></a>
<FONT color="green">226</FONT>            double rollingSumForPeriod = 0.0;<a name="line.226"></a>
<FONT color="green">227</FONT>            for (int i = 0; i &lt; source.getItemCount(); i++) {<a name="line.227"></a>
<FONT color="green">228</FONT>                // get the current data item...<a name="line.228"></a>
<FONT color="green">229</FONT>                TimeSeriesDataItem current = source.getDataItem(i);<a name="line.229"></a>
<FONT color="green">230</FONT>                RegularTimePeriod period = current.getPeriod();<a name="line.230"></a>
<FONT color="green">231</FONT>                rollingSumForPeriod += current.getValue().doubleValue();<a name="line.231"></a>
<FONT color="green">232</FONT>    <a name="line.232"></a>
<FONT color="green">233</FONT>                if (i &gt; pointCount - 1) {<a name="line.233"></a>
<FONT color="green">234</FONT>                    // remove the point i-periodCount out of the rolling sum.<a name="line.234"></a>
<FONT color="green">235</FONT>                    TimeSeriesDataItem startOfMovingAvg <a name="line.235"></a>
<FONT color="green">236</FONT>                        = source.getDataItem(i - pointCount);<a name="line.236"></a>
<FONT color="green">237</FONT>                    rollingSumForPeriod <a name="line.237"></a>
<FONT color="green">238</FONT>                        -= startOfMovingAvg.getValue().doubleValue();<a name="line.238"></a>
<FONT color="green">239</FONT>                    result.add(period, rollingSumForPeriod / pointCount);<a name="line.239"></a>
<FONT color="green">240</FONT>                }<a name="line.240"></a>
<FONT color="green">241</FONT>                else if (i == pointCount - 1) {<a name="line.241"></a>
<FONT color="green">242</FONT>                    result.add(period, rollingSumForPeriod / pointCount);<a name="line.242"></a>
<FONT color="green">243</FONT>                }<a name="line.243"></a>
<FONT color="green">244</FONT>            }<a name="line.244"></a>
<FONT color="green">245</FONT>            return result;<a name="line.245"></a>
<FONT color="green">246</FONT>        }<a name="line.246"></a>
<FONT color="green">247</FONT>    <a name="line.247"></a>
<FONT color="green">248</FONT>        /**<a name="line.248"></a>
<FONT color="green">249</FONT>         * Creates a new {@link XYDataset} containing the moving averages of each <a name="line.249"></a>
<FONT color="green">250</FONT>         * series in the &lt;code&gt;source&lt;/code&gt; dataset.<a name="line.250"></a>
<FONT color="green">251</FONT>         *<a name="line.251"></a>
<FONT color="green">252</FONT>         * @param source  the source dataset.<a name="line.252"></a>
<FONT color="green">253</FONT>         * @param suffix  the string to append to source series names to create <a name="line.253"></a>
<FONT color="green">254</FONT>         *                target series names.<a name="line.254"></a>
<FONT color="green">255</FONT>         * @param period  the averaging period.<a name="line.255"></a>
<FONT color="green">256</FONT>         * @param skip  the length of the initial skip period.<a name="line.256"></a>
<FONT color="green">257</FONT>         *<a name="line.257"></a>
<FONT color="green">258</FONT>         * @return The dataset.<a name="line.258"></a>
<FONT color="green">259</FONT>         */<a name="line.259"></a>
<FONT color="green">260</FONT>        public static XYDataset createMovingAverage(XYDataset source, String suffix,<a name="line.260"></a>
<FONT color="green">261</FONT>                                                    long period, final long skip) {<a name="line.261"></a>
<FONT color="green">262</FONT>    <a name="line.262"></a>
<FONT color="green">263</FONT>            return createMovingAverage(<a name="line.263"></a>
<FONT color="green">264</FONT>                source, suffix, (double) period, (double) skip<a name="line.264"></a>
<FONT color="green">265</FONT>            );<a name="line.265"></a>
<FONT color="green">266</FONT>            <a name="line.266"></a>
<FONT color="green">267</FONT>        }<a name="line.267"></a>
<FONT color="green">268</FONT>    <a name="line.268"></a>
<FONT color="green">269</FONT>    <a name="line.269"></a>
<FONT color="green">270</FONT>        /**<a name="line.270"></a>
<FONT color="green">271</FONT>         * Creates a new {@link XYDataset} containing the moving averages of each <a name="line.271"></a>
<FONT color="green">272</FONT>         * series in the &lt;code&gt;source&lt;/code&gt; dataset.<a name="line.272"></a>
<FONT color="green">273</FONT>         *<a name="line.273"></a>
<FONT color="green">274</FONT>         * @param source  the source dataset.<a name="line.274"></a>
<FONT color="green">275</FONT>         * @param suffix  the string to append to source series names to create <a name="line.275"></a>
<FONT color="green">276</FONT>         *                target series names.<a name="line.276"></a>
<FONT color="green">277</FONT>         * @param period  the averaging period.<a name="line.277"></a>
<FONT color="green">278</FONT>         * @param skip  the length of the initial skip period.<a name="line.278"></a>
<FONT color="green">279</FONT>         *<a name="line.279"></a>
<FONT color="green">280</FONT>         * @return The dataset.<a name="line.280"></a>
<FONT color="green">281</FONT>         */<a name="line.281"></a>
<FONT color="green">282</FONT>        public static XYDataset createMovingAverage(XYDataset source, String suffix,<a name="line.282"></a>
<FONT color="green">283</FONT>                                                    double period, double skip) {<a name="line.283"></a>
<FONT color="green">284</FONT>    <a name="line.284"></a>
<FONT color="green">285</FONT>            // check arguments<a name="line.285"></a>
<FONT color="green">286</FONT>            if (source == null) {<a name="line.286"></a>
<FONT color="green">287</FONT>                throw new IllegalArgumentException("Null source (XYDataset).");<a name="line.287"></a>
<FONT color="green">288</FONT>            }<a name="line.288"></a>
<FONT color="green">289</FONT>            <a name="line.289"></a>
<FONT color="green">290</FONT>            XYSeriesCollection result = new XYSeriesCollection();<a name="line.290"></a>
<FONT color="green">291</FONT>    <a name="line.291"></a>
<FONT color="green">292</FONT>            for (int i = 0; i &lt; source.getSeriesCount(); i++) {<a name="line.292"></a>
<FONT color="green">293</FONT>                XYSeries s = createMovingAverage(<a name="line.293"></a>
<FONT color="green">294</FONT>                    source, i, source.getSeriesKey(i) + suffix, period, skip<a name="line.294"></a>
<FONT color="green">295</FONT>                );<a name="line.295"></a>
<FONT color="green">296</FONT>                result.addSeries(s);<a name="line.296"></a>
<FONT color="green">297</FONT>            }<a name="line.297"></a>
<FONT color="green">298</FONT>    <a name="line.298"></a>
<FONT color="green">299</FONT>            return result;<a name="line.299"></a>
<FONT color="green">300</FONT>    <a name="line.300"></a>
<FONT color="green">301</FONT>        }<a name="line.301"></a>
<FONT color="green">302</FONT>    <a name="line.302"></a>
<FONT color="green">303</FONT>        /**<a name="line.303"></a>