R2 is a forward/inverse solution for 3d or 2d current flow in a quadrilateral or triangular mesh. The inverse solution is based on a regularised objective function combined with weighted least squares (an ‘Occams’ type solution) as defined in Binley and Kemna (2005).

A 32bit and 64bit version for Intel compatible processors are provided in the download.

The current version will work with the following problem size limits:

• Quadrilateral finite element mesh size no larger than 500 nodes in the horizontal or vertical directions;
• The total number of nodes in the mesh is not greater than 40,000;
• The total number of elements in the mesh is not greater than 30,000;
• No more than 200 unique electrode sites;
• No more than 5000 measurements;
• No more than 30,000 parameters