Here are the new parameters to activate in your parameter file to perform a run with a 1D grid. They are the inner and the outer radius of the 1D grid.
For example :

If Rmin1D > Rmin, the 1D grid is only present outside the 2D grid, from Rmax to Rmax1D.

If Rmax1D < Rmax, the 1D grid is only present inside the 2D grid, from Rmin1D to Rmin.

If Rmin1D > Rmin and Rmax1D < Rmax, an error message comes and the code exits.

In fact, Rmin1D is determined by the code. The rings width is given by Rmin, Rmax and Nrad. Then, the smallest possible inner edge radius larger than the input Rmin1D is chosen. Symmetrically, the largest possible radius smaller than the input Rmax1D is chosen for the outer edge of the 1D grid. A message is output :

IINNER is the number of rings between the inner edge of the 1D grid and the inner edge of the 2D grid ; it can be negative if the 1D grid is only present outside the 2D grid. NRAD1D is the total number of rings in the 1D grid.

If NRAD1D is larger than the maximal size of the 1D grids, MAX1D (defined in types.h to be 16384), an error message appears and the code exits.

Important remark :

The 1D grid is not a subsitute for the 2D grid. Therefore, the limits of the latter (Rmin and Rmax) should not be modified with respect to a run with the standard version of FARGO.

If the interface between the two grids happens to be too close to a planet, the disk evolution through the interface may not be smooth.