**Line Graphics Immersed Boundary Data File Format.**

This file contains the positions of the immersed boundary points, and vector and scalar fields defined at those points. The line header file defines the number of immersed boundary entities and the number of attributes for each immersed boundary point in this file.

The data for an immersed boundary point is entirely contained on one line of the file. The data are;

x1 y1 u1 v1 fx1 fy1 ... s11 s12 s13 ... x2 y2 u2 v2 fx2 fy2 ... s21 s22 s23 ... x3 y3 u3 v3 fx3 fy3 ... s31 s32 s33 ... ...

**Notes:**

- 1.
- The first two columns correspond to the immersed boundary points themselves.
- 2.
- The third and fourth columns correspond to the velocity vectors at the immersed boundary points.
- 3.
- The fifth and sixth columns correspond to the force vectors at the immersed boundary points.
- 4.
- The remaining columns correspond to vector field components and scalar field values defined at the immersed boundary points. The number of vector fields and scalar fields is defined in the header file.
- 5.
- In the current version of IBIS, no vector fields other than velocity and force are computed, and no scalar fields are computed. However, if at some future time other fields are needed the structure of the file will not need to change.