使用Rserve從java中調用R

Rserve安裝和加載：

> install.packages('Rserve')

> library(Rserve)

在R中啓動：
> Rserve()
Starting Rserve:

 "D:\PROGRA~2\R\R-31~1.0\library\Rserve\libs\i386\Rserve.exe" 

或者在命令行下啓動：

R CMD Rserve

Rserve: Ok, ready to answer queries.

新建一個java工程，加載jar包：

    - REngine.jar

    - RserveEngine.jar

這兩個包在安裝目錄的R\R-3.1.0\library\Rserve\java目錄下

java測試代碼：

public class PhonePrediction {
    public static void main(String[] args) throws RserveException, REXPMismatchException {
        RConnection re = new RConnection("127.0.0.1");
        REXP x = re.eval("R.version.string");
        System.out.println(x.asString());
        double[] arr = re.eval("rnorm(20)").asDoubles();
        for (double a : arr) {
            System.out.print(a + ",");
        }
        //保存爲圖像文件
        File tempFile = null;
        try {
            re.assign("x", arr); 
            tempFile = File.createTempFile("test-", ".jpg");
            String filePath = tempFile.getAbsolutePath();
            re.eval("jpeg('d://test-1.jpg')");
            re.eval("plot(x)"); 
            re.eval("dev.off()");
        } catch (IOException e) {
            e.printStackTrace();
        } catch (REngineException e) {
            e.printStackTrace();
        } finally {
            re.close(); 

        }
    }
}

輸出結果：

R version 3.1.0 (2014-04-10)

1.0430051899098896,0.671152708470419,0.03148965245438613,1.787869887719384,-2.08155433250965,-1.4168523658229992,-0.8520930614700867,-0.7301950652654462,1.4214651003583285,0.10718589295501241,-0.5064964081419379,-1.0498486125440167,0.1824419576545006,-0.8918871851488132,-0.4150752116861583,-0.7139279436213399,0.06678515999067902,-1.1849271689141667,-0.05695413043401658,0.12468011012699255,

對應的圖像文件test-1.jpg：