#Errors and warnings

The library raises one of three error classes, all in errors.js and exported from the package. A malformed mesh, a non-finite value or a point outside the mesh is always one of them, never a silent wrong answer. Catch them by class:

import { ValidateError, ProjectError, SingularError } from 'traceprojector';

try {
  projector.project(u, point, tIdx, 0);
} catch (error) {
  if (error instanceof ValidateError) { /* the input mesh or arguments are wrong */ }
  else if (error instanceof ProjectError) { /* the call cannot be answered */ }
  else if (error instanceof SingularError) { /* a local problem has no solution */ }
  else throw error;
}

#ValidateError

The input is invalid: the mesh, or an argument that describes a mesh or an element.

Recovery: fix the input. For a flipped tetrahedron, swap two of its vertex numbers.

#ProjectError

The arguments are well formed but the call cannot be answered.

Recovery: check the field at the reported point; locate the point with Locator before projecting; use CanonicalProjector or HigherOrderProjector for higher degrees.

#SingularError

A local linear problem has no solution or the matrix is not definite.

Recovery: the mesh is too coarse near the reported entity for the local problem to exist, or it has a degenerate element. Refine it, or repair the element.

#Weight Warnings

Weight logs warnings via an injected warn function rather than throwing, because per-vertex failures should not halt the entire computation. Construct with { strict: true } to opt into fail-fast behaviour: in that mode the same per-simplex failure path re-throws a ProjectError instead of emitting a warning.

Recovery: Inspect the mesh near the reported simplex for degenerate or inverted elements.

#Bubble Warnings

Bubble also warns rather than throwing for singular mass matrices.

Recovery: Ensure the tetrahedron has strictly positive volume.

#Solver Warnings

Solver warns on ill-conditioned local solves rather than throwing.

Recovery: Inspect the local star geometry for inverted or degenerate

• elements.

#Projector Warnings

Projector warns at construction if the mesh contains degenerate or near-degenerate tetrahedra.

Recovery: Re-mesh or repair the input mesh before computing projections.