# Motivation

- None of the generally available visualization packages currently display higher-order solutions (quadratic, cubic, etc.) natively.
- To work around this limitation, MOOSE can "oversample" a higher-order solution by projecting it onto a finer mesh of linear elements.
- **Note: This is not mesh adaptivity, nor does it improve the solution's accuracy in general.**
- The following slide shows a sequence of solutions oversampled from a base solution on second-order Lagrange elements.

[](---)
# Input File Syntax

- Oversampling is handled via the 'refinements' input parameter, which by default is set to zero. 
- To enable oversampling set this to a positive integer
- The following input file snippet creates an [Exodus II][1] file with two oversample refinements. It also includes a positional offset for the oversampled mesh. 

```text
[Outputs]
  console = true
  exodus = true
  [./exodus_oversample]
     type = Exodus
     refinements = 2
     file_base = oversample
     position = '1 2 0'
  [../]
[]
```

[](---)
# Oversample Example

[](.left-33[)

[](image:98 width:210px)
[image:98]
    refinements = 0

[](])
[](.left-33[)

[](image:99 width:210px)
[image:99]
    refinements = 1

[](])
[](.right-33[)

[](image:100 width:210px)
[image:100]
    refinements = 2

[](])
[](.left-33[)

[](image:101 width:210px)
[image:101]
    refinements = 3

[](])
[](.left-33[)

[](image:102 width:210px)
[image:102]
    refinements = 4

[](])
[](.right-33[)

[](image:103 width:210px)
[image:103]
    refinements = 5

[](])

[](---)

- It is important to note that oversampling will **not improve the solution!**
- The solution on the left is solved on a "coarse" grid.
- The solution in the center is the same as on the left, but has been oversampled for visualization purposes.
- The solution on the right is for the same problem, but solved on a finer mesh (and is therefore closer to the true solution).

[](.left-33[)
[](image:98 width:210px)
[image:98]
    refinements = 0

[](])
[](.left-33[)

[](image:103 width:210px)
[image:103]
    refinements = 5

[](])
[](.right-33[)

[](image:104 width:210px)
[image:104]
    "Fine" grid

[](])