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NDSolve::bcedge NDSolveValue::bcedge ParametricNDSolve::bcedge ParametricNDSolveValue::bcedge

NDSolve::bcedge NDSolveValue::bcedge ParametricNDSolve::bcedge ParametricNDSolveValue::bcedge

Details

  • This message is generated when the boundary conditions in the specification of the solution of a partial differential equation are given at points that are not on the edge of the domain of the solution.
  • Off[message] switches off the message; On[message] switches it on. For example: Off[NDSolve::bcedge].

Examples

Basic Examples  (1)

This input generates a warning message because of the condition on f[0,0]:

Wolfram Language code: sol = NDSolve[{Derivative[2, 0][f][x, t] == Derivative[0, 2][f][x, t], f[0, 0] == 0, f[1, t] == 0, f[x, 0] == x(x - 1), f[0, t] == 0, Derivative[0, 1][f][x, 0] == 0}, f, {x, 0, 1}, {t, 0, 4}];

The problem can be resolved by simply discarding the condition on f[0,0], since this condition is redundant with other equations in the input:

Wolfram Language code: sol = NDSolve[{Derivative[2, 0][f][x, t] == Derivative[0, 2][f][x, t], f[1, t] == 0, f[x, 0] == x(x - 1), f[0, t] == 0, Derivative[0, 1][f][x, 0] == 0}, f, {x, 0, 1}, {t, 0, 4}];

Evaluation of this input will show a plot of the solution:

Wolfram Language code: Plot3D[Evaluate[f[x, t] /. sol[[1]]], {x, 0, 1}, {t, 0, 4}]