How To Overwrite/update A Jama Matrix In Android Studio Without Any Error?

Jama Matrices are defined in my code (Matrix computation class) as follows: private Matrix A; private Matrix B; private Matrix C; The matrix A is initialized as follows: A = new M

Solution 1:

Looking at the source code provided with JAMA, the IllegalArgumentException is thrown at that place:

/** Linear algebraic matrix multiplication, A * B
   @param B    another matrix
   @return     Matrix product, A * B
   @exception  IllegalArgumentException Matrix inner dimensions must agree.
   */public Matrix times(Matrix B) {
      if (B.m != n) {
         thrownewIllegalArgumentException("Matrix inner dimensions must agree.");
      }
      MatrixX=newMatrix(m,B.n);
      double[][] C = X.getArray();
      double[] Bcolj = newdouble[n];
      for (intj=0; j < B.n; j++) {
         for (intk=0; k < n; k++) {
            Bcolj[k] = B.A[k][j];
         }
         for (inti=0; i < m; i++) {
            double[] Arowi = A[i];
            doubles=0;
            for (intk=0; k < n; k++) {
               s += Arowi[k]*Bcolj[k];
            }
            C[i][j] = s;
         }
      }
      return X;
   }

So appearently C.times(B) fails, which means that C and B dimensions do not agree. As we can also see from the line below, C = new Matrix(2,2) does have 2x2 size, which means that B must have a wrong size.

I do not understand what you mean with "matrix overwriting"? C = A.plus(C.times(B)) does allocate a new instance of Matrix internally. This has nothing to do with static or final.

Please provide a complete, minimal example. There are many parts missing, like the place where B is initialized.