java - LIBMSVM svm_node format -

Hi, I am currently working on a project and started using the LIBSVM () library to train datasets for my Java application.

I have a question about svm_problem and svm_node

in the svm_problem we have the following code

  package libsvm; Public class svm_problem applies java.io.Serializable {public int l; Public double [] y; Public svm_node [] [] x; }   
 Is it correct to say that  
 
 
 Does all represent the size of the image?   
 
 In my case, the image is labeled I + 1 / -1    
 and now svm_node [] [] About my second question goes to X  
  package libsvm; Public class svm_node applies java.io.Serializable {public int index; Public double value; }   
 From 1 to i each svm_node is located in every array where I have the number of my properties.  
 So for example I have an image value as follows <1 p> 1: 1.5 2: 2.5 3: 4.5  
 -1 1: 1 2: 2 3: 3  
 then my int l = 3  
 y  
 y [0] = 1  
 y [1] = -1 < / P> 
 X [0] [0] .index = 1  
 x [0] [0] .value = 1.5  
 x [0] [1]. Index = 2  
 X [0] [1] .value = 2.5  
 x [0] [2]. Index = 3  
 x [0] [2] .value = 4.5  
 x [1] [0]. Index = 1  
 x [1] [0] .value = 1  
 x [1] [1]. Index = 2  
 x [1] [1] .value = 2  
 x [1] [2] .index = 3  
 X [1] [2] .value = 3  
 Am I correct in my understanding?   
 
 
 You are locked.  
 svm_problem.l is the number of samples in the database, so in this situation it will be 2.  
 Since libsvm uses a rare sign, therefore, the line ends with the indicator of -1 for each example, for example:  
 x [0] [ 0]. Index = 1  
 x [0] [0] .value = 1.5  
 X [0] [1] .index = 2  
 x [0] [1] .value = 2.5  
 X [0] [2]. Index = 3  
 x [0] [2] .value = 4.5  
 x [0] [3]. Index = -1