Synrad tutorial: adding lattice functions = [BXY file documentation](https://molflow.web.cern.ch/node/119) Reminder on lattice formulas:   # Adding BXY file to Region 1 This example modifies the gradient dipole from the [previous example](https://codimd.web.cern.ch/s/9D7mLLzNO). Instead of ideal beam, change the parameters to the following: - Emittance=6E-8cm (**attention: units are in cm**) - V/H coupling: 20% - BXY file: create and refer to it by its filename  The BXY file is below:  `Z` means beam lattice functions are referenced by the Z coordinate The following lines are all in `Z_coord BetaX(cm) BetaY(cm)` format, Synrad linearly interpolates between them. First and last values are kept outside the defined region (so the first line `0 100 100` is not necessary.) The region below shows an increased beam size, as expected, at Z=30 and Z=50 (middle of first bend and middle of straight section)