Question

我正在运行scala应用程序，并希望使用Renjin调用R文件，并将值从scala传递给R文件。当我从scala加载R文件时，我发现错误上没有找到laply包。如果有人可以告诉我如何使用Renjin将R包加载到scala中，那将会很棒。

以下是我在scala中使用Renjin

调用R文件的代码

使用以下命令
复制带有依赖项的jar文件
scala -cp renjin-script-engine-0.7.0-RC6-jar-with-dependencies.jar
现在scala解释器启动了。

导入javax.script。; import org.renjin.sexp。;

val factory = new ScriptEngineManager（）;

//创建一个R引擎

val engine = factory.getEngineByName("Renjin");

//评估磁盘上的R脚本

engine.eval(new java.io.FileReader("myscript.R"));

在此步骤中，错误连续找不到功能＆＃39; lapply＆＃39;

如何向Renjin添加包。我在哪里添加类路径。

以下是R档

score.sentiment = function (sentences, pos.words,neg.words, .progress='none')
{
  require(plyr)
  require(stringr)

  scores =  laply(sentences, function(sentence,pos.words,neg.words){

    sentence = gsub('[[:punct:]]','',sentence)
    sentence = gsub('[[:cntrl:]]','',sentence)
    sentence = gsub('\\d+','',sentence)
    sentence = tolower(sentence)

    word.list = str_split(sentence, '\\s+')
    words = unlist(word.list)

    pos.matches = match(words, pos.words)

    neg.matches = match(words, neg.words)

    pos.matches = !is.na(pos.matches)

    neg.matches = !is.na(neg.matches)

    score = sum(pos.matches) - sum (neg.matches)

    return(score)

  },pos.words, neg.words, .progress = .progress)

  scores.df = data.frame(score=scores, text=sentences)

  return(scores.df)

}

问题的第二部分是如何将参数从scala控制台传递到此R文件。

例如，这里的句子是一条推文。我想从scala将它发送到R函数。

Answer 1

我不相信plyr或stringr可与Renjin一起开箱即用。我还没有检查过，但我认为plyr对GNU R的C Api起了很大的作用，Renjin似乎choke对某些字符串的测试函数。

但是，我不认为你在上面的函数中需要任何一个包，只需要从基础包中分别使用sapply和strsplit替换laply和str_split。

如上所述，一旦您评估了函数定义，就可以使用[invokeFunction]（http://docs.oracle.com/javase/7/docs/api/javax/script/Invocable.html#invokeFunction(java.lang.String，java.lang.Object从Scala / Java调用此函数。。））方法：

((Invocable)engine).invokeFunction("score.sentiment", 
       "Best pizza EVER!",
       new String[] { "best", "cool" },
       new String[] { "sucks", "awful" });

Renjin会将字符串数组转换为StringVector对象（R字符对象），但您也可以自己创建StringVector对象。

http://docs.oracle.com/javase/7/docs/api/javax/script/Invocable.html#invokeFunction(java.lang.String，java.lang.Object ...）

Answer 2

我能够使用jvmr在scala中使用r包。下面是一个示例代码。

package org.scala.rtest

import org.ddahl.jvmr.RInScala

object RIntegration {
    def main(args: Array[String]) {
       val R = RInScala()
       R>"""
            require(sparkR)

            score.sentiment = function(sentences, pos.words, neg.words, .progress='none')
                {
                  require(plyr)
                  require(stringr)


                  scores = laply(sentences, function(sentence, pos.words, neg.words) {

                    # clean up sentences with R's regex-driven global substitute, gsub():

                    sentence = gsub('[[:punct:]]', '', sentence, ignore.case=T)

                    sentence = gsub('[[:cntrl:]]', '', sentence, ignore.case=T)

                    sentence = gsub('\\d+', '', sentence, ignore.case=T)

                    # and convert to lower case:

                    sentence = tolower(sentence)

                    # split into words. str_split is in the stringr package

                    word.list = str_split(sentence, '\\s+')

                    # sometimes a list() is one level of hierarchy too much

                    words = unlist(word.list)

                    # compare our words to the dictionaries of positive & negative terms

                    pos.matches = match(words, pos.words)
                    neg.matches = match(words, neg.words)

                    # match() returns the position of the matched term or NA
                    # we just want a TRUE/FALSE:

                    pos.matches = !is.na(pos.matches)

                    neg.matches = !is.na(neg.matches)

                    # and conveniently enough, TRUE/FALSE will be treated as 1/0 by sum():

                    score = sum(pos.matches) - sum(neg.matches)

                    return(score)

                  }, pos.words, neg.words, .progress=.progress )
                  scores.df = data.frame(score=scores, text=sentences)
                  return(scores.df)
                } 


       """

        R(" x <- scan('positive-words.txt',what='character',comment.char=';')")
        R(" y <- scan('negative-words.txt',what='character',comment.char=';')")
        R(" z <- scan('twitterstream1.txt', what='character' )")

        R.eval("df <- score.sentiment(z,x,y)")  
        println(R.capture("df"))

        }
}

希望这对某人有所帮助。

Answer 3

爪哇：

构建专为renjin编译的软件包版本。然后使用maven或其他构建工具将其添加到类路径中。

查看Renjin文档的简介以获取更多信息：

http://docs.renjin.org/en/latest/introduction.html#using-cran-packages-in-renjin

在Scala或Java中将包加载到Renjin中

3 个答案: