Find difficulties to install a package

Question

Hello
I need to install a new package: jmat.jar
I put the jmat.jar in /lib directory, but when I import this package in the programm below:
import jmat.data.*;
import jmat.data.matrixDecompositions.EigenvalueDecomposition;
public class PCA {
private Matrix covariance;
private Matrix EigenVectors;
private Matrix EigenValues;
public PCA(Matrix X) {
covariance = new RandomMatrix(X).cov();
EigenvalueDecomposition e = covariance.eig();
EigenVectors = e.getV();
EigenValues = e.getD();
after compiling: javac PCA.java
I have this error: "package jmat.data.* not found in import"
Can U help me.
Thanks

Answer 1

1. Are there classes in jmat.data ?
YES
2. Did you restart your machine yet since putting the file in the classpath.
YES
3. To make it automatic, it needs to be in lib/ext not just lib in the JRE directory.
I create a directory "ext/" in "lib/" directory
I put the file jmat.jar in "ext/" directory .... it does not work