Java 无法更新arrayList中的元素
我有两个矩阵用于特征和权重元素。我正在实现一个学习算法。我想更新arraylist的元素(表示一个特征样本的向量)。下面是代码。但是我的矩阵元素(向量元素)没有更新。我也放了样品溶液。更新前后的值不应相同。你能告诉我代码中的漏洞在哪里吗Java 无法更新arrayList中的元素,java,arraylist,machine-learning,Java,Arraylist,Machine Learning,我有两个矩阵用于特征和权重元素。我正在实现一个学习算法。我想更新arraylist的元素(表示一个特征样本的向量)。下面是代码。但是我的矩阵元素(向量元素)没有更新。我也放了样品溶液。更新前后的值不应相同。你能告诉我代码中的漏洞在哪里吗 for(int i =0 ; i< N ; i++){ //N is a large real number ArrayList<Double> featureVector = new ArrayList<Double&
for(int i =0 ; i< N ; i++){ //N is a large real number
ArrayList<Double> featureVector = new ArrayList<Double>();
featureVector = FeatureMatrix.get(i);
System.out.println("Before::"+ featureVector);
if(testList.contains(i)){
for(int j=0 ; j< testList.size(); j++){
if(i == testList.get(j)){
int indexInTestList= j;
List<Double> subListNextCandidate ;
subListNextCandidate = weightVectorNextCandidate.subList((10*indexIntTestList),((10)*(indexInTestList+1))); //clips a portion of member from long list of members
List<Double> approxWeight = new ArrayList<Double>();
approxWeight = getApproxWeight(FeatureVector, indexInTestList, FeatureMatrix,WeightMatrix, bias); //approxWeight is a vector of same dimension as of featureVector
for(int l=0 ; l< 10;l++){
double Update = featureVector.get(l)+ Rate*((subListCandidate.get(l)-approxWeight.get(l))-(lambda*featureVector.get(l)*(1/M)));//M is large real number
featureVector.set(l,Update);
}
}
}
}
else{
for(int l=0 ; l< 10;l++){
double Update = featureVector.get(l) -Rate*(lambda*featureVector.get(l)*(1/M));
featureVector.set(l, Update);
}
}
System.out.println("After:::"+ FeatureMatrix.get(i) );
}
我只能想出几个合理的理由来解释为什么会发生这种情况:
一定要使用断点,它将是一个救命稻草…testList.get(j)的返回类型是什么?你把一个整数和我怀疑的双精度进行比较。这不太可能顺利…您应该使用调试器并逐步完成代码中的行。1。格式化代码2。
testList
来自哪里?(您发布的代码中没有初始化。)测试列表作为方法的参数出现。
Before::[0.04539928251182193, -0.16233604402485394, 0.905018369795912, -1.2817141994528614, 0.7065420460225843, -0.8946090188977665, -1.74892020689701, -2.1539901172158187, 1.8229765478806985, -1.8109945435256574]
After:::[0.04539928251182193, -0.16233604402485394, 0.905018369795912, -1.2817141994528614, 0.7065420460225843, -0.8946090188977665, -1.74892020689701, -2.1539901172158187, 1.8229765478806985, -1.8109945435256574]