我想对非常长的文本行进行分类。字符串。
我遇到的错误如下：
Exception in thread "main" java.lang.IllegalStateException: No input instance format definedat weka.filters.unsupervised.attribute.StringToWordVector.input(StringToWordVector.java:681)at org.berlin.weka.test.TestWeka.main(TestWeka.java:61)这是我的代码，但我一直遇到异常，可能设置有问题。
package org.berlin.weka.test;import weka.classifiers.Classifier;import weka.classifiers.functions.SMO;import weka.core.Attribute;import weka.core.FastVector;import weka.core.Instance;import weka.core.Instances;import weka.filters.Filter;import weka.filters.unsupervised.attribute.StringToWordVector;public class TestWeka { /* * java -cp %WEKA_HOME% weka.classifiers.meta.FilteredClassifier -t ReutersAcq-train.arff -T ReutersAcq-test.arff -W "weka.classifiers.functions.SMO -N 2" -F "weka.filters.unsupervised.attribute.StringToWordVector -S" */ public static void main(final String [] args) throws Exception { System.out.println("Running"); final StringToWordVector filter = new StringToWordVector(); final Classifier classifier = new SMO(); // Create numeric attributes. final String[] keywords = { "test1", "test2"}; FastVector attributes = new FastVector(keywords.length + 1); for (int i = 0 ; i < keywords.length; i++) { attributes.addElement(new Attribute(keywords[i])); } // Add class attribute. final FastVector classValues = new FastVector(2); classValues.addElement("miss"); classValues.addElement("hit"); attributes.addElement(new Attribute("Class", classValues)); final Instances data = new Instances("Data1", attributes, 100); data.setClassIndex(data.numAttributes() - 1); /////////// Instance instance = new Instance(10); instance.setDataset(data); // instance.setValue(testset.attribute(0),testset.attribute(0).addStringValue(obj.toString())); System.out.println("==>." + data.attribute(0)); instance.setValue(data.attribute(0), data.attribute(0).addStringValue("test1")); instance.setDataset(data); // Add class value to instance. instance.setClassValue(1.0); // Add instance to training data. data.add(instance); // Use filter. filter.input(instance); Instances filteredData = Filter.useFilter(data, filter); // Rebuild classifier. classifier.buildClassifier(filteredData); }} // End of the class //回答：
你可以尝试先设置输入格式，如下所示：
//rest of your code
// Use filter
filter.input(instance);
filter.setInputFormat(data); //你要输入到过滤器的数据实例
Instances filteredData = Filter.useFilter(data, filter);
例如，你可以参考http://weka.wikispaces.com/Use+WEKA+in+your+Java+code 并移除过滤器。（注意他们在将实例传递给过滤器之前设置了过滤器的输入格式）
