我是 Java 开发领域的初学者，但我仍然是 Java 编程的学习者。我想在 netbeans IDE 上查看支持向量机分类器的输出。因此，我复制了这段附加的代码，并尝试使用所有其他必需的类和主要方法来运行，但是当我在Number format exception调用loadBinaryProblem()main 方法，如果我删除所有逗号并将它们替换为空格 ex: 23 25 26 27 那么我得到的是ArrayIndexOutOfBound异常而不是它。所以任何人都可以帮助正确地获得输出而不会出现任何错误。
package svmlearn;
import java.io.*;
import java.util.*;
/**
* Class representing an optimization problem (a data setting);
* taken from liblinear; "bias" excluded
* @author miafranc
*
*/
public class Problem {
/** The number of training data */
public int l;
/** The number of features (including the bias feature if bias >= 0) */
public int n;
/** Array containing the target values */
public int[] y;
/** Map of categories to allow various ID's to identify classes with. */
public CategoryMap<Integer> catmap;
/** Array of sparse feature nodes */
public FeatureNode[][] x;
public Problem() {
l = 0;
n = 0;
catmap = new CategoryMap<Integer>();
}
/**
* Loads a binary problem from file, i.e. having 2 classes.
* @param filename The filename containing the problem in LibSVM format.
*/
public void loadBinaryProblem(String filename) {
String row;
ArrayList<Integer> classes = new ArrayList<Integer>();
ArrayList<FeatureNode []> examples = new ArrayList<FeatureNode []>();
try {
BufferedReader r = new BufferedReader(new FileReader(filename));
while ((row = r.readLine()) != null) {
String [] elems = row.split(" ");
//Category:
Integer cat = Integer.parseInt(elems[0]);
catmap.addCategory(cat);
if (catmap.size() > 2) {
throw new IllegalArgumentException("only 2 classes allowed!");
}
classes.add(catmap.getNewCategoryOf(cat));
//Index/value pairs:
examples.add(parseRow(elems));
}
x = new FeatureNode[examples.size()][];
y = new int[examples.size()];
for (int i=0; i<examples.size(); i++) {
x[i] = examples.get(i);
y[i] = 2*classes.get(i)-1; //0,1 => -1,1
}
l = examples.size();
} catch (Exception e) {
System.out.println(e);
}
}
/**
* Parses a row from a LibSVM format file.
* @param row The already split row on spaces.
* @return The corresponding FeatureNode.
*/
public FeatureNode [] parseRow(String [] row) {
FeatureNode [] example = new FeatureNode[row.length-1];
int maxindex = 0;
for (int i=1; i<row.length; i++) {
String [] iv = row[i].split(":");
int index = Integer.parseInt(iv[0]);
if (index <= maxindex) {
throw new IllegalArgumentException("indices must be in increasing order!");
}
maxindex = index;
double value = Double.parseDouble(iv[1]);
example[i-1] = new FeatureNode(index, value);
}
if (n < maxindex)
n = maxindex;
return example;
}
}