java - 线程 "main"java.lang.RuntimeException : Matrix is singular 中的异常

Question

我只是想根据 JAMA 文档创建一个 3x3 矩阵的逆矩阵。但每次它都会给我以下错误 -

线程“main”中的异常 java.lang.RuntimeException:矩阵是奇异的

谁能在这方面帮助我？

Answer 1

Jama 的文档不是很好。

事实上，如果你查看源代码，你会发现 Matrix.inverse() 最终调用了 LUDecomposition.solve(...) 并且代码说:

  270      /** Solve A*X = B
  271      @param  B   A Matrix with as many rows as A and any number of columns.
  272      @return     X so that L*U*X = B(piv,:)
  273      @exception  IllegalArgumentException Matrix row dimensions must agree.
  274      @exception  RuntimeException  Matrix is singular.
  275      */
  277      public Matrix solve (Matrix B) {
  278         if (B.getRowDimension() != m) {
  279            throw new IllegalArgumentException("Matrix row dimensions must agree.");
  280         }
  281         if (!this.isNonsingular()) {
  282            throw new RuntimeException("Matrix is singular.");
  283         }

正如维基百科所说:

"In linear algebra an n-by-n (square) matrix A is called invertible or nonsingular or nondegenerate, if there exists an n-by-n matrix B such that AB = BA = I_n where I_n denotes the n-by-n identity matrix and the multiplication used is ordinary matrix multiplication."

简而言之，单数意味着不可逆。

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如果您对 JAMA 不满意，请查看 Apache Commons 数学库，尤其是 Linear Algebra module .