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General::luc

Details

  • This message is generated by a failure in the algorithm that is used in computing numerical solutions of linear systems of equations.
  • Off[message] switches off the message; On[message] switches it on. For example: Off[General::luc].

Examples

Basic Examples  (1)

An error occurs because the underlying matrix is ill-conditioned:

Wolfram Language code: m = HilbertMatrix[20]; b = m.Table[1, {20}]; LinearSolve[N[m], N[b]]

The condition number of the matrix can be obtained as the third element of the result of LUDecomposition. A large value of the condition number indicates that the matrix is ill-conditioned:

Wolfram Language code: lud = LUDecomposition[N[m]]; Last[lud]

The solution is more accurate if sufficiently high precision is used:

Wolfram Language code: LinearSolve[N[m, 30], N[b, 30]]