## PLTMG

### Summary

PLTMG is a package for solving elliptic partial differential equations in general regions of the plane. It is based on continuous piecewise linear triangular finite elements, and features adaptive local mesh refinement, multigraph iteration, and pseudo-arclength continuation options for parameter dependencies. It also provides options for solving several classes of optimal control and obstacle problems. The package includes an initial mesh generator and several graphics packages. Support for the Bank-Holst parallel adaptive meshing strategy is also provided. PLTMG is provided as Fortran (and a little C) source code, in both single and double precision versions. The code has interfaces to X-Windows, MPI, and Michael Holst’s OpenGL image viewer SG. The X-Windows, MPI, and SG interfaces require libraries that are NOT provided as part of the PLTMG package.

### Authors

Randolph E. Bank

### Vendor

Department of Mathematics University of California, San Diego La Jolla, California, USA 92093-0112

### Links

### Status

officially approved by the authors### Aims and scope

### Mathematical Classification

### Keywords

- 3d graphics
- adaptive feedback loop
- adaptive grid generation
- adaptive mesh refinement
- adaptive mesh smoothing
- adaptive mesh unrefinement
- adaptive refinement
- algebraic multigrids
- alternate function
- a posteriori error estimation
- arcs
- biconjugate gradient
- bifurcation points
- coefficient functions
- conjugate gradient
- conjugate gradients
- continuation problem
- continuous piecewise linear triangular finite elements
- convection-diffusion-reaction equation
- curved edges
- Dirichlet vertex number
- domain decomposition
- dual function
- edges
- elliptic boundary value problem
- elliptic eigenvalue problem
- elliptic partial differential equations
- elliptic PDE
- error estimates
- features adaptive local mesh refinement
- finite elements
- graphics
- graphs
- interior point method
- Lagrange multiplier
- matrices
- matrix
- mesh partitioning
- mesh smoothing
- moving finite elements
- MPI
- multigraph iteration
- multilevel solver
- Newton iteration convergence
- Newton's method
- nonsymmetric gradient
- normalization equations
- obstacle problem
- optimal control problem
- parallel adaptive solver
- parallel mesh generation
- parameter identification problem
- pde constrained optimization
- plots
- pseudo-arclength continuation
- pseudo-arclength continuation options for parameter dependencies
- skeleton
- sparce matrices
- sparse factorization
- superconvergence
- surface plots
- symmetric gradient
- tangent function
- time pie chart
- triangulation
- unstructured mesh generation
- vector plots
- vertices