Grid generation with Pyroms

[hetienne]

Hello ROMS and Pyroms users.
I try to create a new ROMS grid using pyroms.
I don't have any trouble with horizontal grid.
I the use these code lines to generate vertical grid:
grd_name = 'W_AFRICA4'
grd_out='W_AFRICA4_grd.nc'
theta_b = 0.1
theta_s = 10.0
Tcline = 50
N = 40
vgrd = pyroms.vgrid.s_coordinate_4(hc, theta_b, theta_s, Tcline, N, hraw=hraw)
# ROMS grid
grd = pyroms.grid.ROMS_Grid(grd_name, hgrd, vgrd)
# write grid to netcdf file
pyroms.grid.write_ROMS_grid(grd, filename=grd_out)

When plotting, I obtain the following:

Then, if I try to load the grid (grid= pyroms.grid.get_ROMS_grid('W_AFRICA4')) and try to plot it again with the same script, the result is different:

Do someone have an idea of what happen?
Thank you for your help.

[frederic]

Etienne,
Can you please check that the parameters (theta_b, theta_s, ...) in your gridid file are consistant with the parameters used to generate the vertical grid?
Thanks,
Frederic