CODEWITHSUNDEEP
javaweka
Raj
Raj

Reputation: 41

Converting a CSV file to ARFF with weka.jar

For my project, I am using weka.jar. I am converting a CSV file to ARFF using following code: 

import weka.core.Instances;
import weka.core.converters.ArffSaver;
import weka.core.converters.CSVLoader;

import java.io.File;

public class CsvArffConverter
{

 public static void Convert(String sourcepath,String destpath) throws Exception
 {
 // load CSV
 CSVLoader loader = new CSVLoader();
 loader.setSource(new File(sourcepath));
 Instances data = loader.getDataSet();

 // save ARFF
 ArffSaver saver = new ArffSaver();
 saver.setInstances(data);
 saver.setFile(new File(destpath));
 saver.setDestination(new File(destpath));
 saver.writeBatch();
 }
 public static void main(String args[]) throws Exception
 {
 Convert("C:\\ad\\BSEIT.csv", "C:\\ad\\test.arff");

 }
}

However, on executing, I am getting following error: 

Cannot create a new output file. Standard out is used.
Exception in thread "main" java.io.IOException: Cannot create a new output file (Reason: java.io.IOException: File already exists.). Standard out is used.
    at `enter code here`weka.core.converters.AbstractFileSaver.setDestination(AbstractFileSaver.java:421)
    at Predictor.CsvArffConverter.Convert(CsvArffConverter.java:29)
    at Predictor.CsvArffConverter.main(CsvArffConverter.java:34)

Upvotes: 4

Views: 2334

Answers (1)

Atilla Ozgur
Atilla Ozgur

Reputation: 14701

According to weka mail list, this error is a file issue, may be permission. Other emails suggest to use Java I/O approch to save arff file.

This error is coming from the CSVSaver and indicates that it is unable 
to create the directory and/or file that you've specified. More than 
likely it is something to do with permissions on where it is trying to 
write to.

Try following code.

import weka.core.Instances;
import weka.core.converters.ArffSaver;
import weka.core.converters.CSVLoader;

import java.io.File;

public class CsvArffConverter
{
    public static void Convert(String sourcepath,String destpath) throws Exception
    {
        // load CSV
        CSVLoader loader = new CSVLoader();
        loader.setSource(new File(sourcepath));
        Instances dataSet = loader.getDataSet();

        // save ARFF
        BufferedWriter writer = new BufferedWriter(new FileWriter(destpath));
        writer.write(dataSet.toString());
        writer.flush();
        writer.close(); 
    }

    public static void main(String args[]) throws Exception
    {
        Convert("BSEIT.csv", "test.arff");
    }
}

As you can see, I use relative paths. Since absolute path writing may be blocked due to permission issues.

Upvotes: 3

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