Continuity Basis Form

Select Mesh→Edit→Basis to open the Basis form....

The Basis form is used to select the finite element basis (interpolation) functions that will be required for the current model. 1D, 2D and 3D linear, quadaratic and cubic Lagrange or cubic Hermite basis functions are available to add to a list that appears as a pop-up menu for each variable in the Node and Boundary Conditions forms.

Lagrange/Hermite

  • In this panel you can add either Lagrange or Hermite tensor-product basis functions. For each type, you can choose from 1D, 2D, or 3D basis functions. Lagrange functions have only nodal values as parameters. Hermite functions are cubic interpolation functions with derivative as well as value parameters at each node.
  • Click the appropriate drop-down list depending on whether you want to add Lagrange or Hermite

  • Select a function
  • Enter the desired number of integration points (see below)
  • Click the Add [basis fuction] button to add to the list. The selected function will be appended to the listbox on the left.

Number of integration/collocation points

  • Enter a value for each variable. Which fields you can fill in will depend on whether a 1D, 2D or 3D basis function was selected. [Insert purpose of these fields here]

  • These fields can be changed when adding a new function (as above)
  • These fields can also be changed for an existing funtion
    • Select the function to change from the list
    • Modify the points as needed
    • Click on Change [basis function]

    • Make sure to reselect <<add basis function>> to prevent accidental change of an existing function

Shift Up/Down

  • These buttons can be used to change the order of the selected function in the list. The order of the basis functions chosen will determine their order of appearance in the menu of the Nodes Form where the first choice will be the default.

Subtract

  • This button will delete the highlighted function from the list.