Why does the Jama matrix inner dimension agree in the first iteration, but later it does not?

Question

Following Jama Matrices are defined in my code:

P: 3*3 Matrix
I: 3*3 identity Matrix
K: 3*2 Matrix
H: 2*3 Matrix
Q: 3*3 Matrix

Following is my code snippet:

private Matrix getP() {
        P= (I.minus(K.times(H))).times(Q);
        Log.d("csv", "P is calculated");
        return P;
    }

While running the code, at first iteration it works, i.e, P is calculated is printed at the Logcat. However, it happens only once and the application gets stopped. Following is the error:

 java.lang.IllegalArgumentException: Matrix inner dimensions must agree.

If the Matrix inner dimension was the error, how come it runs for the first iteration? I obtained some information about the inner dimension at this link. However, I could not figure out the solution. When the equation is manually checked, the matrix dimension matches. Anything wrong with my approach??

Thank you.

Answer 1

您介意显示您的通话方式getP吗？无论我单击多少次，以下内容均有效fab。

class MainActivity : AppCompatActivity() {

    val I = Matrix.identity(3,3)
    val K = Matrix(3,2,5.0)
    val H = Matrix(2,3,7.0)
    val Q = Matrix(3,3,8.0)

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        fab.setOnClickListener { view ->
            getP()
        }
    }

    private fun getP():Matrix{
        val P = (I.minus(K.times(H))).times(Q)
        Log.d("MainActivity","P is calculated")
        return P
    }
}

什么时候getP退货，您将结果存储在哪里？您是否可能覆盖其中一个矩阵？

更新资料

如果您的情况是使变量成为最终变量不是您的选择，则可以记录每个矩阵的维，然后调试变化的维。

private fun getP():Matrix{
    Log.d(TAG,"I dimension: ${I.rowDimension} x ${I.columnDimension}")
    Log.d(TAG,"K dimension: ${K.rowDimension} x ${K.columnDimension}")
    Log.d(TAG,"H dimension: ${H.rowDimension} x ${H.columnDimension}")
    Log.d(TAG,"Q dimension: ${Q.rowDimension} x ${Q.columnDimension}")

    val P = (I.minus(K.times(H))).times(Q)
    Log.d(TAG,"P is calculated")
    return P
}